Assignment 3

Rotational & Vibrational

Atomic Spectrum

3Assignment Electromagnetic
( 6)Topic
Spectrum
CHE FATIMAH NADIA
BINTI CHE JUSOH The range of frequencies of
S51064 electromagnetic radiation and their
FIZ4107 respective wavelengths and photon
energies.

&Differences of Stokes Raman Differences of
-Anti Stokes Raman
&Emission Spectrum
Stokes lines are of longer wavelength than
that of the exciting radiation responsible for Absorption Spectrum
the fluorescence or Raman effect while anti-
Stokes lines are found in fluorescence and in That absorption lines are where
Raman spectra when the atoms or molecules light has been absorbed by the
of the material are already in an excited state atom thus you see a dip in the
(as when at high temperature). spectrum whereas emission
spectra have spikes in the
Differences of Spontaneous spectra due to atoms releasing
photons at those wavelengths.
&Emission Stimulated Emission

Spontaneous emission takes place without interaction with other photons,
and the direction and phase are random while stimulated emission takes

place when the excited electron interacts with another photon.

References

Difference between Emission and Absorption Spectra. Retrieved January 24, 2021, from the byjus website:
https://byjus.com/physics/difference-between-emission-and-absorption-spectra/
Lock, J. A. (2015). Scattering of the evanescent components in the angularspectrum of a tightly focused electromagneticbeam by a
spherical particle. Journal of Quantitative Spectroscopy & Radiative Transfer, 162(2015), 95-102. doi:
http://dx.doi.org/10.1016/j.jqsrt.2014.12.019
National Aeronautics and Space Administration (NASA). (2013). The Electromagnetic Spectrum. Retrieved from
https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
Retrieved January 24, 2021, from the Britannica website: https://www.britannica.com/science/Stokes-lines
Retrieved January 24, 2021, from the Fiber Labs Inc. website: https://www.fiberlabs.com/glossary/stimulated-emission/

ATOMIC PHYSICS

Assignment 3 : Topic 6
by : Nik Aisyah Najwa Binti Abdullah (S51106)

Q1 - What is the electromagnetic spectrum?

-The word used by researchers to define the full amount of light that occurs around us, both seen and unseen.

Q2 - What is the differences between emission spectrum and absorption spectrum?

Emission Spectrum Absorbtion Spectrum
Generated when energy is released by atoms. Generated when energy is absorbed by atoms.
Include colored lines throughout the spectrum. Compose dark lines or holes in the spectrum.
It is useful in determining the composition of a Can be used to determine the ability of certain
objects to retain heat and its level of absorption.
specific matter. The wavelengths of light absorbed is helpful in
The form of photons emitted helps to establish the figuring out the number of substances in the
type of elements that the material is made of since
each element radiates a different amount of energy sample

and has a specific degree of emission.

Q3 - What is the differences between Stokes Raman and Anti-Stokes Raman?

Stokes Raman Anti-Stokes Raman
The frequency of the scattered radiation is lower The frequency of the scattered radiation is higher

than the frequency of the incident radiation. than the frequency of the incident radiation.

Q4 - What is the differences between spontaneous emission and stimulated emission?

Spontaneous Emission Stimulated Emission
Occurs without interaction with other photons, and Stimulated emission occurs when the excited

the direction and phase are random. electron interacts with another photon.
Occurs regardless of whether or not population Occurs only when the gain medium is pumped

inversion exists. sufficiently and the population inversion is
generated.

References

Christopher , C. (2019, September 7). What is the Electromagnetic Spectrum? EarthSky.
https://earthsky.org/space/what-is-the-electromagnetic-spectrum.
Admin. (2020, August 25). Difference Between Emission and Absorption Spectra - Comparison Chart. BYJUS.
https://byjus.com/physics/difference-between-emission-and-absorption-spectra/.
Masayoshi , H. (2000). Stimulated and spontaneous emission. Fiberlabs Inc.
https://www.fiberlabs.com/glossary/stimulated-emission

Nurafifa Ruqayyah Binti Rushdan S51368 Topic 6

ROTATIONAL AND VIBRATIONAL
ATOMIC SPECTRUM

Electromagnetic spectrum

The range of frequencies of electromagnetic radiation and their respectives
wavelengths and photon energies

Differences between emission spectrum and absorption spectrum

The emission spectrum has different coloured lines in the spectrum while absorption spectrum
has dark-coloured lines in the spectrum.
Emission spectrum happens when atoms release energy while absorption spectrum happens
produced when atoms absorb energy.
The type of photons emitted in emission spectrum is helpful in figuring out the composition of a
certain matter, while absorption spectrum is helpful in figuring out the ability of certain objects to
retain heat and its absorption level.

Differences between Stokes Raman and Anti-Stokes Raman

Stokes Raman are scattered photons that are reduced in energy relative while Anti-Stokes Raman
are scattered photons that are increased in energy relative to the incident photons that
interacted with the molecule.
For Stokes Raman, the incident photons interact with a ground state molecule and form a virtual
state, while for Anti-Stokes Raman, the incident photons interact with a molecule that is
vibrationally excited.
When the temperature increased, the intensity of the Stokes Raman decrease, while the intensity
of the Anti-Stokes Raman will increase.

Differences between spontaneous emission and stimulated emission

Spontaneous emission does not require an external electromagnetic stimulus to release energy,
while stimulated emission required external electromagnetic stimuli to release energy.
Only one energy wave is released during spontaneous emission while during stimulated emission,
two energy waves are released.

References

Charles, A., 2020. Chem. Libretexts: Raman Spectroscopy. Retrieved from https://chem.libretexts.org/Raman_Spectroscopy
Maria, 2014. Differences between spontaneous and stimulated emission. Retrieved from https://www.differencebetween.com/difference-between-spontaneous-
and-vs-stimulated-emission/
Spectrum. Retrieved from https://malaysia.images.search.yahoo.com/search/images
National Aeronautics and Space Administration. The electromagnetic spectrum. Retrieved from https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html

Rotational & Vibrational
atomic spectrum

Electromagnetic Spectrum

The electromagnetic spectrum (EM) is the set of all forms of EM radiation.

Differences between emission Differences between Stokes Raman and

spectrum and absorption spectrum Anti-Stokes Raman

The distinction between absorption When the photon contributes
and emission spectra is that the energy to the chemical bond in
absorption lines are where the light Raman scattering, a change in
has been absorbed by the atom so wavelength occurs, while when the
that we can see a dip in the photon gains energy from the
spectrum, whereas the emission bond, an anti-Stoke shift in
spectra have spikes in the spectra wavelength occurs.
due to the photon-releasing atoms
at those wavelengths.

Differences between spontaneous emission

and stimulated emission

Spontaneous emission occurs without
interaction with other photons, and the
direction and phase are random while the
stimulated emission occurs when the
excited electron interacts with another
photon.

REFERENCES DDZZAAFFIIRRAAHH BBIINNTTII DDZZUULLKKAARRNNAAIINN

Irigoyen, J., & Herraez, J. (2003). Electromagnetic spectrum and color vision. In 3rd International SS5511669977
Symposium on Image and Signal Processing and Analysis, 2003. ISPA 2003. Proceedings of the (Vol. 2, pp.
626-629). IEEE.
Pan, Z., Ning, L., Cheng, B. M., & Tanner, P. A. (2006). Absorption, excitation and emission spectra of
SrCl2: Eu2+. Chemical physics letters, 428(1-3), 78-82.
Simon, C., Weihs, G., & Zeilinger, A. (2000). Optimal quantum cloning via stimulated emission. Physical
review letters, 84(13), 2993.
Krafft, C., Dietzek, B., Popp, J., & Schmitt, M. (2012). Raman and coherent anti-Stokes Raman scattering
microspectroscopy for biomedical applications. Journal of biomedical optics, 17(4), 040801.

IRDINA SYAFINAZ BINTI MOHD NORSHAM (S51803)

ROTATIONAL AND VIBRATIONAL

ATOMIC SPECTRUM

What is the electromagnetic spectrum?

Electromagnetic spectrum is the entire distribution of electromagnetic radiation according to frequency or wavelength. Although
all electromagnetic waves travel at the speed of light in a vacuum, they do so at a wide range of frequencies, wavelengths, and

photon energies. The electromagnetic spectrum comprises the span of all electromagnetic radiation and consists of many
subranges, commonly referred to as portions, such as visible light or ultraviolet radiation

Differences

Emission Spectrum Absorption Spectrum

Spectrum of the Spectrum obtained by transmitting
electromagnetic radiation electromagnetic radiation through a
emitted by a substance
Produced when atoms release substance
Produced when atoms absorb
energy
Show coloured lines energy
An emission spectrum is given Show dark lines or gaps
when an excited atom obtains a An atom obtains a higher energy
lower energy level level when an absorption spectrum is

given by that atom

Stokes Raman Anti-Stokes Raman

Scattered photons that are reduced in Scattered photons that are increased
energy relative to the incident photons in energy relative to the incident
photons that interacted with the
that interacted with the molecule molecule.
The incident photons interact with a
The incident photons interact with a
ground state molecule and form a molecule that is vibrationally excited.

virtual state. The scattered photons come from
The scattered photons come from molecules that end up in the ground
molecules that end up in excited state, thereby explaining why they are
vibrational states of the ground state, higher in energy than the incident
thereby explaining why they are lower
in energy than the incident photons. photons.

Spontaneous Stimulated
Emission Emission

Emission of light photon Emission of light photon is by
takes place immediately inducement of a photon having
energy equal to the emitted photon
without any
inducement energy
Polychromatic radiation Monochromatic radiation
Incoherent radiation
Less directionality Coherent radiation
Less intense High directionality

High intense

REFERENCES Richard, A. (2016). Lasers Light Amplification by Stimulated Emission of Radiation snistforum.com. – ppt download. from
https://slideplayer.com/slide/11673171/
Anonymous. Electromagnetic spectrum. From https://www.britannica.com/science/electromagnetic-spectrum
Madhusha (2017). Difference Between Absorption and Emission Spectra: Definition, Characteristics, Comparison. From
https://pediaa.com/difference-between-absorption-and-emission-spectra/
Wenzel, T. (2020). Raman Spectroscopy. From https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Book%3A_Molecular_and_At
omic_Spectroscopy_(Wenzel)/5%3A_Raman_Spectroscopy

SITI NURAISAH BT SARIFUDIN (S52027)
ATOMIC PHYSICS (FIZ4107)

LECTURER'S NAME: DR. KHADIJAH HILMUN KAMARUDIN
TOPIC 6

Q1: What is the electromagnetic Q2: What are the differences between emission
spectrum? spectrum and absorption spectrum?

The electromagnetic spectrum (EMS) is EMISSION SPECTRUM ABSORPTION SPECTRUM
the whole distribution of electromagnetic
radiation wavelengths ranging from short Defined as a spectrum of Defined as a spectrum obtained
wavelength (high frequency) gamma rays electromagnetic radiation by transmitting electromagnetic
to long-wavelength (low frequency) radio emitted by a substance radiation through a substance
waves.

Produced when atoms release Produced when atoms absorb
energy energy

Show colored lines Show dark lines or gaps

An emission spectrum is given An atom obtains a higher energy
when an excited atom obtains level when an absorption
a lower energy level spectrum is given by that atom

Account for the wavelengths Account for wavelengths
emitted by a substance absorbed by a substance

Q3: What are the differences between Stokes
Raman and Anti-Stokes Raman?

STOKES RAMAN ANTI-STOKES RAMAN

Defined as an inelastic Defined as an inelastic scattering Q4: What are the differences between
scattering process that transfers process that transfers energy spontaneous emission and stimulated emission?
energy from the photon to from the molecular vibration to
molecular vibration photon SPONTANEOUS STIMULATED
EMISSION EMISSION
Effect on a molecule is the Effect on a molecule is de-
excitation of vibrations or excitation of pre-excited Defined as a result of the Defined as the process in which
rotations vibrations transition of an atom from the photons are used to stimulate
excited state to the lower atom in an excited state to fall
Effect on the photon is the Effect on the photon is the energy state which happens down to a lower energy state
change in direction and has a change in direction and has a due to the natural tendency of
higher wavelength higher wavelength the atom to attain minimum
energy
Probability of occurrence is very Probability of occurrence is very
rare rare

No external agent is involved Photons need to be incident as
stimuli

Results in ordinary light Can be utilized to get Laser beam

Light obtained is not coherent Light obtained is coherent

REFERENCES

Horning, N. (2019). Remote Sensing. In Encyclopedia of Ecology (pp. 404–413). Elsevier.

Kauffmann, T. H., Kokanyan, N., & Fontana, M. D. (2019). Use of Stokes and anti‐Stokes Raman
scattering for new applications. Journal of Raman Spectroscopy, 50(3), 418–424.

Szalay, L., Rabinowitch, E., Murty, N. R., & Govindjee. (1967). Relationship between the Absorption and Emission
Spectra and the “Red Drop” in the Action Spectra of Fluorescence In Vivo. Biophysical Journal, 7(2), 137–149.

https://byjus.com/physics/difference-between-emission-and-absorption-spectra/

https://www.fiberlabs.com/glossary/stimulated-
emission/#:~:text=Spontaneous%20emission%20takes%20place%20without,electron%20interacts%20with%20a
nother%20photon

T6 ROTATIONAL VIBRATIONAL SPECTRUM

SITI NUR IZZATI BINTI MAZLAN (S52046)

The electromagnetic spectrum is the complete spectrum (or continuum) of all
forms of “light”
The electromagnetic spectrum consists of electric and magnetic fields which
vibrates - thus making waves
The electromagnetic spectrum consists of radio waves, cell phone waves,
microwaves, radar waves, infrared waves, visible light waves, ultraviolet
waves, x-ray waves, gamma waves

Emission Spectrum Atomic Absorption Emission Spectroscopy
VS Measure trace metal
Measure trace metal concentrations in complex
Absorption Spectrum concentrations in complex matrices
matrices Atomic emission depends upon
Atomic absorption depends upon the number of excited atoms
the number of ground state atoms

Stokes Anti Stokes Stokes
Anti VSStokes
The frequency of scattered lines is The frequency of scattered lines is

less than that if incident light more than that of incident

Caused by molecules at lower energy Caused by molecules at higher energy

level which are more populated level which are less populated
These are more intense with high These are less intense with low
intensity of absorption intensity of absorption

Spontaneous Spontaneous Stimulated
VS Emission of light photon takes
place immediately without any Emission of a light photon is by
Stimulated Emission inducement inducement of a photon having
Polychromatic radiation energy equal to the emitted photon
Incoherent radiation energy
Less directionality Monochromatic radiation
Coherent radiation
High directionality

REFERENCES

Arya, U. (2017,
December 15). Raman spectroscopy. Retrieved January 22, 2021, from slideshare:https://www.slideshare.net
/urvashiarya1/raman-spectroscopy-84144504

Dr Anurag Yadav. (2015, August 9). spectrophotometry- atomic absorption and flame emission.
Retrieved January 22, 2021, from slideshare: https://www.slideshare.net/anurag_yadav/photometry-iii-anu

Parker, J. (2010, March 3). The Electromagnetic Spectrum. Retrieved January 22, 2021, from slideshare:
https://www.slideshare.net/jan_parker/the-electromagnetic-spectrum

Richard, A. (2018, January 18). L A S E R S L LIGHT AAMPLIFICATION by SSTIMULATED EEMISSION of RADIATION.
Retrieved Janary 23, 2021, from slideplaye.com: https://slideplayer.com/slide/11673171/

RRoottaattiioonnaall aanndd vviibbrraattiioonnaall

INDIE MUSIC FESTIVAL
aattoommiicc ssppeeccttrruumm

>>>what is the electromagnetic spectrum<<<

The electromagnetic (EM) spectrum is the range of all types of EM
radiation. The human eye can only detect only asmall portion of this
spectrum called visible light. Electromagnetic energy travels in waves and
spans a broad spectrum from very long radio waves to very short gamma
rays.
Radiation is the energy that travels and spreads out as it goes. The entire
distribution of electromagnetic radiation according to frequency or
wavelength.

>>> Differences <<<

Emission spectrum

· A spectrum of the radiation emitted by a substance.
· Has different colored lines in the spectrum.
· It is helpful in figuring out the composition of a certain matter.
· Can emit all the colors in an electromagnetic spectrum.
· When energy is absorbed by electrons of an atom, electrons move from lower energy levels to
higher energy levels. These excited electrons have to radiate energy to return to ground states from
the excited state, which is unstable.

Absorption spectrum -Anti Stokes Raman

· Spectrum obtained by transmitting electromagnetic radiation through a substance. · Found in fluorescence and in Raman spectra when the atoms or molecules of the
· Has dark-colored lines in the spectrum. material are already in an excited state.
· Can be used to figure out the ability of certain objects to retain heat and its absorption level. · Has greater energy. Has a shorter wavelength than that of the light that produces
· Can have a few colors missing due to the redirection of absorbed photons. them.
· An absorption spectrum is constituted by the frequencies of light transmitted with dark · The energy of the scattered radiation is more than the incident radiation.
bands when energy is absorbed by the electrons in the ground state to · Much less intense than the Stokes line. This occurs because only molecules that are
reach higher energy states. vibrationally excited prior to irradiation can give rise to the anti-Stokes line.

Stokes Raman Virtual states

· Radiation of particular wavelengths presents in the line spectra associated with Energy
fluorescence and the Raman effect.
· Occurs at lower energy (longer wavelength) than that of the exciting radiation Vibrational states
responsible for the fluorescence or Raman effect. Ground states
· The energy of the scattered radiation is less than the incident radiation.
· More intense Stokes line is normally measured.

Rayleigh Stokes Raman Anti stokes
scattering scattering Raman scattering

Spontaneous emission Stimulated emission

· An atom in the excited state is induced to return to the ground state, thereby · The atom in an excited state returns to the ground state thereby emitting a
resulting in two photons of same frequency and energy is called Stimulated photon, without any external inducement is called Spontaneous emission.
emission. · The emitted photons move in all directions and are random.
· The emitted photons move in the same direction and is highly directional. · The radiation is less intense and is no phase relationship between them.
· The radiation is highly intense monochromatic and coherent. · The photons are not in phase, there is no phase relationship between them.
· The photons are in phase, there is a constant phase difference.

REFERENCES

Admin. (2020, August 25). Difference Between Emission and Absorption Spectra

- Comparison Chart. Retrieved January 25, 2021, from

https://byjus.cFomO/RphyTsiIcsC/dKifEfeTreSnc eW-bWetWw.eeRn-EeAmiLssLioYn-GanRdE-aAbsTorSpItioTnE- .COM / 123-456-7890

spectra/

What are the bAasPicRpIrinLcip3les0of  Ra|ma1n 0SpPecMtro|scop1y?2(3n.d.A). NReYtrWieHveEdRJEanuSarTy REET, ANY CITY

25, 2021, from https://andor.oxinst.com/learning/view/article/raman-

spectroscopy

Principle of Spontaneous and Stimulated emission - Einstein's Quantum theory of ZAFIRAH BINTI SHAMSUDIN
radiation. (n.d.). Retrieved January 25, 2021, from

http://www.brainkart.com/article/Principle-of-Spontaneous-and-Stimulated- >S52120<
emission---Einstein---s-Quantum-theory-of-radiation_6881/

NURUL SHAQQINAH BINTI P.RAMLI (S52161)

ROTATIONAL AND VIBRATIONAL
ATOMIC SPECTRUM

Electromagnetic spectrum

The electromagnetic (EM) spectrum is the range of all types of EM radiation. Radiation is energy that travels and spreads out as it goes
– the visible light that comes from a lamp in your house and the radio waves that come from a radio station are two types of

electromagnetic radiation. The other types of EM radiation that make up the electromagnetic spectrum are microwaves, infrared light,
ultraviolet light, X-rays and gamma-rays.

Emission spectrum Differences Absorption spectrum

Occurs when an electron jumps from higher orbital to lower Occurs when an electron jumps from lower to higher orbital by
orbital by releasing energy. releasing energy.
Comprise coloured lines in the spectrum. Comprise dark lines or gaps in the spectrum.
It is helpful in figuring out the composition of a certain matter. Can be used to figure out the ability of certain objects to retain
The type of photons emitted is helpful in figuring out the kind of heat and its absorption level.
elements the substance is made of as each element radiates a The wavelengths of light absorbed is helpful in figuring out the
different amount of energy and has a unique emission level. number of substances in the sample

Stokes Raman Anti-Stokes Raman

The frequency of the scattered radiation is lower than the frequency of The frequency of the scattered radiation is higher than the frequency of
the incident radiation. the incident radiation.
The incident photons interact with a ground state molecule and form a The incident photons interact with a molecule that is vibrationally
virtual state. excited. The virtual state produced by this interaction has more energy
The scattered photons come from molecules that end up in excited than the virtual state produced when the incident photon interacted with
vibrational states of the ground state, thereby explaining why they are a ground state molecule.
lower in energy than the incident photons. The scattered photons come from molecules that end up in the ground
state, thereby explaining why they are higher in energy than the incident
photons.

Spontaneous emission Stimulated emission

The atom in the excited state returns to the ground state An atom in the excited state is induced to return to the ground
thereby emitting a photon, without any external inducement. state, thereby resulting in two photons of same frequency and
The emitted photons move in all directions and are random. energy.
The radiation is less intense and is incoherent. The emitted photons move in the same directions and is highly
The photons are not in phase, there is no phase relationship directional.
between them. The radiation is highly intense monochromatic and coherent.
The photons are in phase, there is a constant phase different.

REFERENCES Gaur, A., Singh, S., & Lotha, G. (2019). Electromagnetic spectrum. Retrieved January 18, 2021, from
https://www.britannica.com/science/electromagnetic-spectrum
Lotha, G. (2018). Stokes lines. Retrieved January 18, 2021, from https://www.britannica.com/science/Stokes-lines
Mitofsky, A. M. (2020). Difference Between Emission and Absorption Spectra - Comparison Chart. Retrieved January 18, 2021,
from https://byjus.com/physics/difference-between-emission-and-absorption-spectra/

FIZ4107
ASSIGNMENT 3

Muhammad Aimi Asyraf bin Ahmad
S52750

WHAT IS ELECTROMAGNETIC SPECTRUM?

The electromagnetic (EM)
spectrum is the range of all types

of EM radiation. Radiation is
energy that travels and spreads
out as it goes. Electromagnetic
energy travels in waves and spans
a broad spectrum from very long
radio waves to very short gamma

rays.

DIFFERENCE BETWEEN EMISSION & ABSORPTION
SPECTRUM

Emission spectrum is produced when atoms release
energy, comprise of coloured lines in the spectrum,
and is helpful in figuring out the composition of a
certain matter.
Absorption spectrum is produced when atoms absorb
energy, comprise of dark lines in the spectrum, and is
helpful in figuring out the ability of certain objects to
retain heat and its absorption level.

DIFFERENCE BETWEEN STOKES & ANTI-STOKES RAMAN

When the photon transfers energy to the chemical
bond in Raman scattering, a Stokes shift in

wavelength occurs, whereas when the photon gains
energy from the bond, an anti-Stokes shift in

wavelength occurs. Stokes scattering is a more
likely occurrence because the vast majority of
molecules are in the ground vibrational state as

described by the Boltzmann distribution.

DIFFERENCE BETWEEN SPONTANEUOS AND STIMULATED
EMISSION

Spontaneous emission takes place without interaction with other photons,
and the direction and phase are random. It takes place only when the gain
medium is pumped strongly enough and population inversion is created.
Stimulated emission, on the other hand, takes place when the excited
electron interacts with another photon. Both the direction and phase are
“copied” from the other photon when stimulated emission takes place. It
takes place no matter population inversion exists or not.

REFERENCES

1.Electromagnetic Spectrum - Introduction. (2013). Nasa.gov.
https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html

2.Admin. (2019, February 10). Difference Between Emission And Absorption Spectra. BYJUS; BYJU’S.
https://byjus.com/physics/difference-between-emission-and-absorption-spectra/

3.Li, ZY & Chen, Dong-Ming & He, TJ & Liu, FC. (2005). Difference between Stokes and anti-Stokes Raman shifts and time-
reversal symmetry. Chinese Journal of Chemical Physics. 18. 695-701.

4.Stimulated and spontaneous emission | Fiberlabs Inc. (2018). Fiberlabs Inc. https://www.fiberlabs.com/glossary/stimulated-
emission/#:~:text=Properties%20of%20photons%20generated%20by,electron%20interacts%20with%20another%20phot
on.

FIZ 4107 ASSIGNMENT 3

ELECTROMAGNETIC SPECTRUM IMAN SYAKIR BIN IBRAHIM
S54112

is the entire distribution of electromagnetic
radiation according to frequency or

wavelength .The entire electromagnetic
spectrum consists from the lowest to the

highest frequency and from longest to
shortest wavelength includes the involved
spectrum likes radio waves, microwaves,
infrared radiation, visible light, ultraviolet

radiation, X-rays, and gamma rays.

EMISSION SPECRTUM VS ABSORPTION SPECTRUM SSEEPPMMEEICICSSTTSSRRIIOOUUNNMM AASSBBPPSSEEOOCCRRTTPPRRTTUUIIOOMMNN

A MOLECULE RETURNS TO A STATE OF A MOLECULE IS EXCITED FROM A LOWER
LOWER ENERGY E1 FROM AN EXCITED ENERGY STATE TO A HIGHER ENERGY STATE
STATE OF ENERGY E2 BY EMITTING A
BY ABSORBING A PHOTON AS THE
PHOTON. FREQUENCY OF THE INCIDENT RADIATION
PRODUCED WHEN ATOMS RELEASE ENERGY
IS SWEPT OVER A RANGE
COMPRISE COLOURED LINES IN THE PRODUCED WHEN ATOMS ABSORB ENERGY
SPECTRUM
COMPRISE DARK LINES OR GAPS IN THE
THE TYPE OF PHOTONS EMITTED IS SPECTRUM
HELPFUL IN FIGURING OUT THE KIND OF
ELEMENTS THE SUBSTANCE IS MADE OF AS THE WAVELENGTHS OF LIGHT ABSORBED IS
EACH ELEMENT RADIATES A DIFFERENT HELPFUL IN FIGURING OUT THE NUMBER
AMOUNT OF ENERGY AND HAS A UNIQUE
OF SUBSTANCES IN THE SAMPLE
EMISSION LEVEL

SSRRTTAAOOMMKKAAEENNSS STOCKES RAMAN VS ANTI-STOCKES RAMAN

AANNTTRRII-A-ASSMMTTAAOONNKKEESS

THE FREQUENCY OF THE SCATTERED THE FREQUENCY OF THE SCATTERED

RADIATION IS LOWER THAN THE RADIATION IS HIGHER THAN THE

FREQUENCY OF THE INCIDENT RADIATION. FREQUENCY OF THE INCIDENT RADIATION

ORIGINATED FROM A MOLECULE AT LOWER CAUSED BY MOLECULES AT HIGHER ENERGY

ENERGY LEVEL

HIGH INTERNSITY DUE TO HIGH AMOUNT LESS INTENSITY DUE TO LOW AMOUNT OF

OF ABSORPTION ABSORPTION

TAKES PLACE MORE FREQUENTLY WHEN IN MOLECULE RAISED TO HIGHER ENERGY

LOW TEMPERATURE STATE WHEN IN HIGH TEMPERATURE THUS

MAKES THEM SLOWLY INCREASES AND

SPONTANEOUS EMISSION VS STIMULATED EMISSION SSPPOOEENNMMTTIISSAASSNNIIOOEENNOOUUSS BECOME PROMINENT

A MOLECULE IN AN EXCITED STATE WILL SSTTEEIIMMMMUUIISSLLSSAAIIOOTTNNEEDD
DECAY TO A LOWER ENERGY STATE
WITHOUT ANY STIMULUS FROM THE AN EM RADIATION INCIDENT UPON A
OUTSIDE MOLECULE IN AN EXCITED STATE CAN
THE PHOTON EMITTED DUE TO CAUSE THE MOLECULE TO DECAY TO A

SPONTANEOUS EMISSION CAN MOVE IN ANY LOWER ENERGY STATE
DIRECTION THE PHOTON EMITTED DUE TO
STIMULATED EMISSION CAN MOVE ONLY IN
DEPENDS ONLY ON THE PROPERTIES OF THE DIRECTION OF THE INCIDENT PHOTON
THE TWO ENERGY LEVEL BETWEEN WHICH DEPENDS ON THE PROPERTIES OF THE TWO
ENERGY LEVEL INVOLVED IN THE
TRANSITION OCCURS TRANSITION AS WELL AS ON THE ENERGY
DENSITIES OF INCIDENT RADIATION.
THE STIMULATED EMISSION IS THE
FUNDAMENTAL PHYSICAL PROCESS OF THE

OPERATION OF THE LASER

REFERENCES

Admin. (2019, February 10). Difference Between Emission And Absorption Spectra. Retrieved from BYJUS website:

https://byjus.com/physics/difference-between-emission-and-absorption-spectra/

The Editors of Encyclopedia Britannica. (2019). electromagnetic spectrum | Definition, Diagram, & Uses. In Encyclopædia

Britannica. Retrieved from https://www.britannica.com/science/electromagnetic-spectrum

ABDULLAH HARITH S54276

TOPIC 6:

ELECTROMAGNETIC
SPECTRUM

Definition

Entire distibution of electromagnetic radiation according to wavelength
and frequency

Emission spectrum Absorption spectrum

produced when atom released produced when atom absorb
energy energy
comprised coloured line in comprised dark line/gaps in
spectrum spectrum
allows to figure composition of figures object absorption level and
matter ability to retain heat
helps in identifying element of helps in identifying number of
substances substances in the sample

EmSistosikoenssRpaemctarnum AbAsnotir-pstoioknespReacmtraunm

Has frequency lower than the Has higher frequency than the
original state because the molecule orignal state because it started as
did not return to its original state an excited energy and return back
to its original state.

SEpmonistasnioeniuspeemcistrsuiomn ASbtimsourplattieodn espmeicsstriounm

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wwitihthoouuttththeeaacctitoionnooffaannyyoouutstsididee aassththaattooffppaarreennttpphhoototonn. .

aaggeenntt

Stokes lines | physics. (n.d.). Encyclopedia Britannica. Retrieved January 22, 2021, References
from https://www.britannica.com/science/Stokes-lines
The difference between spontaneous emissions and stimulated emissions. (n.d.). Www.Testandmeasurementtips.com. Retrieved January 22, 2021, from
https://www.testandmeasurementtips.com/the-difference-between-spontaneous-emissions-and-stimulated-emissions-faq/
The Editors of Encyclopedia Britannica. (2019). electromagnetic spectrum | Definition, Diagram, & Uses. In Encyclopædia Britannica.
https://www.britannica.com/science/electromagnetic-spectrum

Muhammad Yazid bin Mohamad Yasin, S54420 Reference

ELECTROMAGNETIC SPECTRUM Electromagnetic spectrum. (n.d.). Retrieved January 25, 2021, from
https://www.britannica.com/science/electromagnetic-spectrum
WHAT IS ELECTROMAGNETIC Electromagnetic Spectrum. (n.d.). Retrieved January 25, 2021, from https://www.merriam-
SPECTRUM?? webster.com/dictionary/electromagnetic%20spectrum
Urvashi Arya Follow. (2017, December 15). Raman spectroscopy. Retrieved January 25, 2021, from
Electro magnetic spectrum is the entire distribution of electro magnetic https://www.slideshare.net/urvashiarya1/raman-spectroscopy-84144504
radiation extending from gamma rays to the longest radio wave including visible light. Madhusha. (2017, June 22). Difference Between Absorption and Emission Spectra: Definition,
Characteristics, Comparison. Retrieved January 25, 2021, from https://pediaa.com/difference-
The electromagnetic spectrum includes visible light, which alternates at a much between-absorption-and-emission-spectra/
higher frequency than radio waves (Bhaskar Krishnamachari, 2021) Unknown. (2016, November 28). Stimulated emission vs spontaneous emission. Retrieved January
25, 2021, from https://totalecer.blogspot.com/2016/11/stimulated-emission-vs-spontaneous-
emission.html

Difference between emission spectrum and absorption spectrum.

Obtain by transmitting electromagnetic radiation through a Spectrum of the electromagnetic radiation emitted by a
substance. substance.
Produced when atoms absorb energy. Produced when atoms release energy.
Dark lines or gaps. Coloured lines.
Higher energy level. Lower energy level.
Account for wavelength absorbed by a substances. Account for the wavelengths emitted by a substance.

Difference between Stokes Raman and Anti-Stokes Raman.

Stokes Raman Anti-Stokes Raman than
frequency of scattered lines less than Frequency of scattered lines more
incident light. incident light.
Caused by lower energy molecule. Caused by higher level molecules.
More intense with high intensity of Less intense with low intensity of
absorption. absorption.
Preferred low temperatures. Preferred high temperature.

Difference between Spontaneous Emission and stimulated emission.

Natural transition when an atom de-exited Artificial transition when an atom excited
after the end of life times in the higher energy before the end of life times in the higher
level. energy level.
Photon emitted can move in any direction. Photon emitted can only move in direction of
the incident photon.
Depends only on two energy levels between Depends on two energy levels involved in the
which the transition occurred. transition and also on the energy density of
incident radiation.

S54660

Muhammad Irfan Hazim bin Mowardi

Electromagnetic spectrum is the array of all types of
electromagnetic radiation. The visible light that
comes from a lamp in our home and the radio waves
that come from a radio station are two forms of
electromagnetic radiation. Radiation is energy that
moves and expands wherever it passes. (Myers, 2013)

When a molecules return to a state of lower energy A molecule is excited from a lower energy state to a
from an excited state energy by emitting a photon. higher energy state by absorbing a photon as the
frequency of the incident radiation is swept over a
Produced when atoms release energy range.
Comprise coloured lines in the spectrum
It is helpful in figuring out the composition of a Produced when atoms absorb energy
certain matter Comprise dark lines or gaps in the spectrum
(Admin, 2019) Can be used to figure out the ability of certain
objects to retain heat and its absorption level
(Admin, 2019)

For Stokes Raman Spectrum the For Anti-Stokes Raman
frequency of the scattered Spectrum the frequency of the
radiation is lower than the scattered radiation is higher
frequency of the incident than the frequency of the
radiation. incident radiation.

The transition of an electron from the Stimulated emission of radiation is the
excited state to the ground state happens as process whereby photons are used to
a result of the natural tendency of the generate other photons that have exact
electron without the action of any external phase and wavelength as that of parent
agent. photon.

This phenomenon is found in LEDs, This is the key process of formation of
Fluorescent tubes. laser beam.
There is no population inversion of Population inversion is achieved by
electrons in LEDs. various ‘pumping’ techniques to get
amplification giving the LASER its name
“Light amplification by stimulated
emission of radiation.”

Admin. (2019, February 10). Difference Between Emission And Absorption Spectra. Retrieved from BYJUS website: https://byjus.com/physics/difference-between-emission-and-absorption-
spectra/
Differentiate between spontaneous and stimulated emissions. (n.d.). Retrieved from www.ques10.com website: https://www.ques10.com/p/5262/differentiate-between-spontaneous-and-
stimulated-2/
Myers, J. D. (2013, March). Electromagnetic Spectrum - Introduction. Retrieved from imagine.gsfc.nasa.gov website:
https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html#:~:text=The%20electromagnetic%20(EM)%20spectrum%20is

Nadia binti umar ridzuan Electromagnetic (EM) spectrum is the entire
S55289 of eM radiation based on the frequency or wavelength
Fiz4107

All Electromagnetic (EM) waves travels at the
speed of light that is 3 x 10^8

AAGGNNEETTIICCEM spectrum consists of electromagnetic radiation of all
EELLEECCTSTSRPRPEOEOCMCMTTRRUUMM ranges & subranges also called as portion

Radiation with the highest frequency consist of the

shortest wavelength, hence are stronger in radiation.

EM spectrum consist of radio waves, infrared
radiation, visible light, ultraviolet radiation,

X-rays & gamma rays.

ESESMPMPEIEICSCSTSTSRIRIOUOUNMNM helps identify ability Anti-stokes are found
of certain objects to retain in flourescence & raman
Photon emitted helps identify spectra when atoms or
composition & element of heat & absorption level molecules are already in
substance excited state
wavelength of light scattered light of Anti-stokes
Each element radiates absorbed helps in figuring Have higher frequency than
different amount of the number of substances original light
energy with unique emission
level in sample ANTI-S&TOKES
STOKES
Spectrum comprised of Spectrum comprised of
coloured lines dark lines & gaps

produce when atoms produce when atoms
release energy absorb energy

ASBBPSEOOCRTPPRTUUIIMMOONN

SSPPOONNTTAANNOOUUSS EEMMIISSSSIIOONN

Emitted photons photons are not in Stoke lines consist of
move in all & phase with no phase longer wavelenghts
than the excited
random directionsm difference radiation responsible
for the raman or
less intense Atom in an excited flourescence effect
radiation state returns to the
ground state without scattered light of
stokes have lower
any inducement frequency than
original light
SSTTIIMMUULLAATTEEDD EEMMIISSSSIIOONN
REFERENCES
Emitted photons photons are in phase
move in the same with a constant phase 1.Britannica, The Editors of Encyclopaedia. (2019)"Electromagnetic spectrum". Encyclopedia Britannica.
Retrieved on January 20th,2021 at https://www.britannica.com/science/electromagnetic-spectrum.
direction & is difference
highly directional 2.Britannica, The Editors of Encyclopaedia. (2018) "Stokes lines". Encyclopedia Britannica. Retrieved on January
24th, 2021 at https://www.britannica.com/science/Stokes-lines.
Highly intense Atom in the excited state
monochromatic & is induced to return to 3.Byju's. (n.d). Difference between Emission and Absorption Spectra. Retroeved on January 24th, 2021 at
coherent radiatio https://byjus.com/physics/difference-between-emission-and-absorption-spectra/
ground state results to 2
photons of same frequency 4.FiberLabs Inc. (n.d). Stimulated and Spontaneous Emission. Retrived on January 24th, 2021 at
https://www.fiberlabs.com/glossary/stimulated-
& energy emission/#:~:text=Properties%20of%20photons%20generated%20by,electron%20interacts%20with%20anothe
r%20photon.
stimulated emission spontaneous emission



MOHAMAD FAIQ HAZIQ BIN HAMDAN (S55899)

TTOOPPIICC 66::
EELLEECCTTRROOMMAAGGNNEETTIICC

SSPPEECCTTRRUUMM

DDEEFFIINNIITTIIOONN

The entire distribution of electromagnetic radiation
according to frequency or wavelength.

EMISSION SPECTRUM STOKES RAMAN VS SPONTANEOUS

VS ABSORPTION ANTI - STOKES RAMAN EMISSION VS

SPECTRUM STOKES RAMAN STIMULATED EMISSION

EMISSION SPECTRUM The emitted SPONTANEOUS
radiation is of EMISSION
Produced when lower frequency
atoms release than the incident Takes place without
energy radiation interaction with other
Comprise coloured The molecule did photons, and the
lines in the spectrum not return to its direction and phase
figuring out the original state are random.
composition of a Takes place no
certain matter ANTI - STOKES RAMAN matter population
inversion exists or not.
ABSORPTION SPECTRUM The emitted
radiation is of STIMULATED
Produced when higher frequency EMISSION
atoms absorb energy than the incident
Comprise dark lines radiation. Takes place when the
or gaps in the The molecule excited electron
spectrum started as an interacts with another
Figure out the ability excited energy and photon.
of certain objects to return back to its Takes place only
retain heat and its original state when the gain
absorption level medium is pumped
strongly enough and
population inversion

is created

REFERENCES

Admin. (2020, August 25). Difference Between Emission and Absorption Spectra - Comparison Chart. Retrieved January 25,
2021, from https://byjus.com/physics/difference-between-emission-and-absorption-spectra/
(n.d.). Retrieved January 25, 2021, from https://www.sas.upenn.edu/~carrolld/SpecProjectPages/Raman.html
Stimulated and spontaneous emission. (n.d.). Retrieved January 25, 2021, from https://www.fiberlabs.com/glossary/stimulated-
emission/#:~:text=Properties%20of%20photons%20generated%20by,electron%20interacts%20with%20another%20photon.

What is electromagnetic spectrum? Figure 1 shows the electromagnetic spectrum.
Adopted from https://www.uib.no/en/hms-portalen
Electromagnetic spectrum is travel of
electromagnetic energy in waves and spans a /75292/electromagnetic-spectrum
broad spectrum from longest radiowaves to
shortest waves which is gamma ray. Human
eye only detect the visible light which is
only small portion of spectrum.

What is difference between emission spectrum and

absorbtion spectrum?

Absorbtion spectrum are lines of absorbtion which is light
absorbed by atom while Emission spectrum are spiking spectrum

because of released photoms by atoms at a wavelength.

What is difference between Stokes Raman and

Anti Stokes Raman?

Wavelength shift of Stokes Raman occurs when transfer of
photon energy to chemical bond in scattering of Raman while
Wavelength of Anti-Stokes Raman shift occurs when energy
gained by photon from the bond.

What is difference between spontaneous

emission and stimulated emission?

Spontaneous emission happen without any interac
tion with photons, and phase and direction are occur

randomly while stimulated emission happen when
excited electron have interaction with other photon.

References Nurul Nasuha Binti Mohd
Introduction to the Electromagnetic Spectrum | Science Mission Directorate. (2016). Nasa.gov. Rosdi
S56101
https://science.nasa.gov/ems/01_intro

Stimulated and spontaneous emission | Fiberlabs Inc. (2018). Fiberlabs Inc. https://www.fiberlabs.com/glossary/stimulated-
emission/#:~:text=Properties%20of%20photons%20generated%20by,electron%20interacts%20with%20another%20photon.

Emission and absorption spectra | Optical phenomena and properties of matter | Siyavula. (2021). Siyavula.com; Siyavula.
https://intl.siyavula.com/read/science/grade-12/optical-phenomena-and-properties-of-matter/12-optical-phenomena-and-

properties-of-matter-
03#:~:text=The%20difference%20between%20absorption%20and,releasing%20photons%20at%20those%20wavelengths.

Dove Medical Press. (2016, June). Figure 2 Schematic showing the difference between Stokes and... ResearchGate;
ResearchGate. https://www.researchgate.net/figure/Schematic-showing-the-difference-between-Stokes-and-anti-Stokes-

Raman-scattering-
Notes_fig3_304341022#:~:text=When%20the%20photon%20transfers%20energy,in%20wavelength%20occurs.%20...

LEONG GIA XING 01 The electromagnetic spectrum is the range of
S56469 frequencies of electromagnetic radiation and their
What is the respective wavelengths and photon energies. Examples :
ASSIGNMENT 3 electromagnetic microwaves, infrared light, ultraviolet light, X-rays and
spectrum? gamma-rays.

Rotational and 02 Emission spectrum is when electrons back to energy
vibrationalctrum levels. Absorption spectrum is when electrons gain
What is the energy and jump to higher energy levels.
differences between
emission spectrum
and absorption
spectrum?

Sources : https://pediaa.com/difference-between-absorption-and-emission-
spectra/

03 Stokes Raman are of longer wavelength than that of the
exciting radiation responsible for the fluorescence. Anti-
What is the Stokes lines are found in fluorescence and in Raman
differences between spectra when the atoms or molecules of the material are
Stokes Raman and already in an excited state.
anti- stokes Raman?

REFERENCES : 04 Spontaneous emission takes place without interaction
with other photons, and the direction and phase are
1. Atomic Spectra and Atomic Structure By What is the random. Stimulated emission takes place when the
Gerhard Herzberg, John William Tranter differences between excited electron interacts with another photon
Spinks, 1944 spontaneous
emission and
2. Atkins' Physical Chemistry By Peter Atkins, stimulated emission?
Julio de Paula

3.Basic Atomic and Molecular Spectroscopy
By John Michael Hollas



Mustofa Bin Hosen Emission Absorption
S56816
Produced when atoms Produced when atoms
Electromagnetic Spectrum release energy. absorb energy.
Comprise coloured lines in Comprise dark lines or gaps
Electromagnetic waves can be the spectrum. in the spectrum.
classified and arranged according It is helpful in figuring out the Can be used to figure out the
composition of a certain ability of certain objects to
to their various matter. retain heat and its absorption
wavelengths/frequencies The type of photons emitted level.
is helpful in figuring out the The wavelengths of light
kind of elements the absorbed is helpful in figuring
substance is made of as each out the number of
element radiates a different substances in the sample.
amount of energy and has a
unique emission level

RamStoakneVsAsntiR-Satomkaesn Spontaneous Emission
Vs
Inelastic Inelastic
Stimulated
Photon-Molecule
-Energy transfer- Molecule-Photon
Excitation of vibration or
rotations -Effect on molecule- De-excitation of pre excited Emission of a light photon Emission of a light photon
-Effect on photon- vibration or rotations takes place through an takes place immediately
Change in direction higher -Probability of occurrence- inducement, i.e. by an without any inducement.
wavelength Change in direction low external photon. It is a random process.
wavelength It is not a random process. The photons do not get
very rare The photon gets multiplied multiplied through chain
Extremely rare through a chain reaction. reaction.
It is a controllable process. Less intense.
The frequency of the The frequency of the More intense. Polychromatic radiation.
scattered radiation is scattered radiation is Monochromatic radiation

lower than the higher than the
frequency of the frequency of the
incident radiation. incident radiation.

https://www.khanacademy.org/science/ https://byjus.com/physics/d https://wiki.anton-
ap-chemistry/electronic-structure-of- ifference-between- paar.com/en/basic
atoms-ap/bohr-model-hydrogen-
ap/a/light-and-the-electromagnetic- emission-and-absorption- s-of-raman-
spectrum spectra/ spectroscopy/

https://www.slides
hare.net/SIDDHI3
1/laser-34114004



FIZ4107
FIZIK ATOM
ASSIGNMENT 3

Name: Chong Mun Fei
Matrix: S59150

Programme: Financial Mathematics

Question 1:

What is the electromagnetic spectrum?

Electromagnetic spectrum is the entire distribution of
electromagnetic radiation according to frequency or wavelength.
Although all electromagnetic waves travel at the speed of light in a
vacuum, they do so at a wide range of frequencies, wavelengths,
and photon energies. The electromagnetic spectrum comprises the
span of all electromagnetic radiation and consists of many
subranges, commonly referred to as portions, such as visible light or
ultraviolet radiation. The various portions bear different names
based on differences in behaviour in the emission, transmission,
and absorption of the corresponding waves and also based on their
different practical applications. There are no precise accepted
boundaries between any of these contiguous portions, so the ranges
tend to overlap.

Question 2:

What is the differences between emission spectrum and absorption
spectrum?

Emission Spectrum, When energy is absorbed by electrons of an atom, electrons move

from lower energy levels to higher energy levels. These excited electrons have to radiate energy to
return to ground states from the excited state, which is unstable. The emission spectrum is formed
by the frequencies of these emitted light.

Absorption Spectrum, constituted by the frequencies of light transmitted with dark bands

when energy is absorbed by the electrons in the ground state to reach higher energy states.

Emission Spectrum Absorption Spectrum

Produced when atoms release energy Produced when atoms absorb energy

Comprise coloured lines in the Comprise dark lines or gaps in the

spectrum spectrum

It is helpful in figuring out the Can be used to figure out the ability
composition of a certain matter of certain objects to retain heat and
its absorption level

The type of photons emitted is The wavelengths of light absorbed is
helpful in figuring out the kind of helpful in figuring out the number of
elements the substance is made of as substances in the sample
each element radiates a different
amount of energy and has a unique
emission level

Question 3:

What is the differences between Strokes Raman and Anti-Strokes
Raman?

Stokes Raman, radiation of particular wavelengths present in the
line spectra associated with fluorescence and the Raman effect (q.v.).
Stokes Raman are longer wavelength than that of the exciting radiation
responsible for the fluorescence or Raman effect.

Anti-Strokes Raman, are found in fluorescence and in Raman spectra
when the atoms or molecules of the material are already in an excited
state (as when at high temperature). In this case the radiated line energy
is the sum of the pre-excitation energy and the energy absorbed from the
exciting radiation. Anti-Stokes Raman are always shorter wavelength than
that of the exciting radiation responsible for the fluorescence or Raman
effect.

Question 4:

What is the differences between spontaneous emission and
stimulated emission?

Spontaneous Emission Stimulated Emission

Emitting quanta of energy where Process where an external photon of
quantum system undergoes a change a certain frequency, reacts with the
and jumps to a lower energy state. excited electron in an atom and this

results in dropping to lower energy
state.

Found in LEDs and Fluorescent tubes Found in laser, it is the key process
for the formation of a laser beam.

There is no population inversion of population inversion is achieved by
electrons in LEDs. various pumping technique

External stimuli are not required External stimuli are required
Depends only on the upper level of Depends upon the electron being in
the electron the upper level but the electron must
be started at the upper level.

Only one energy wave is released. Two energy waves are released.

Self-emission process of radioactive A single particle or group of particles
materials without any influence of initiated emission in radioactive
radiation. material

Referrence: https://byjus.com/physics/difference-between-emission-and-absorption-spectra/

Referrence:
http://www.ux1.eiu.edu/~cfadd/1160/Ch29Atm/Laser.html

Rotational And Vibrational
Atomic Spectrum

ElectroMagnetic Spectrum:
The range of all types of
electromagnetic radiation.
Consist of microwaves ,
radiowaves , infrared ray , visible
light , ultraviolet ray ,X- ray ,
gamma ray .

Absorption Spectrum: By : LAM JING KIT (S59387)
The electron of atom excited from
lower energy level to higher energy References:
level when absorb photon. 1.National Aeronautics and Space Administration
(2013 , March). The Electromagnetic Spectrum .
Emission Spectrum: Retrieved from
The photon release from an atom with https://imagine.gsfc.nasa.gov/science/toolbox/e
electron in excited state fall to lower mspectrum1.html#:~:text=The%20electromagn
energy level. etic%20(EM)%20spectrum%20is,all%20types%2
0of%20EM%20radiation.&text=The%20other%2
Raman Scattering occur when energy of 0types%20of%20EM,spectrum%20than%20you
photon re emit by molecule change. %20may%20think.
2.Nutt . D (2016 , October 6) . Topic 7: Raman
Strokes Raman occur when the energy Scattering [Video] . Youtube . Retrieved from
of scattered photon decreases. https://youtu.be/1_IqMY6t6w0
Molecules gain the energy to excited 3.FiberLabs Inc. Stimulated and spontaneous
to higher energy level. emission . Retrieved from
Anti-Strokes Raman occur when the https://www.fiberlabs.com/glossary/stimulated-
energy of the scattered photon emission/#:~:text=Properties%20of%20photons%2
increases. 0generated%20by,electron%20interacts%20with%2
0another%20photon.
Spontaneous Emission:
Photon emited and energy level of
atom fall to lower energy level though
decay without external stimulus.

Stimulated Emission:
Photon emited when incident photon
with same energy as different between
2 energy level of the excited electron
in atom trigger the emission occur





NUR SYAFIQAH SYAHMIMIE BINTI AUGUSTINE

TOPIC 6 ROTATIONAL AND
VIBRATIONAL ATOMIC
SPECTRUM

ELECTROMAGNETIC SPECTRUM

The electromagnetic (EM) spectrum is the range of all types of EM radiation.
Radiation is energy that travels and spreads out as it goes – the visible light that
comes from a lamp in your house and the radio waves that come from a radio
station are two types of electromagnetic radiation. The other types of EM
radiation that make up the electromagnetic spectrum are microwaves, infrared
light, ultraviolet light, X-rays and gamma-rays.

EMISSION SPECTRUM ABSORPTION SPECTRUM
Emission is the process of elements Absorption occurs when electrons
releasing different photons of color absorb photons which causes them to
as their atoms return to their lower gain energy and jump to higher energy
energy levels. Atoms emit light when levels. Absorption spectrum occurs when
they are heated or excited at high light passes through a cold, dilute gas
energy levels. When the electrons and atoms in the gas absorb at
return to lower energy levels, they characteristic frequencies; since the re-
release extra energy and that can be emitted light is unlikely to be emitted in
in the form of light causing the the same direction as the absorbed
emission of light. photon, this gives rise to dark lines
(absence of light) in the spectrum.

STOKES RAMAN AND ANTI-STOKES RAMAN
Stokes lines are of longer wavelength than that of the exciting radiation
responsible for the fluorescence or Raman effect. Anti-Stokes lines are found in
fluorescence and in Raman spectra when the atoms or molecules of the material
are already in an excited state (as when at high temperature).

DIFFERENCES BETWEEN SPONTANEOUS
AND STIMULATED EMISSION

Sdipreocnttiaonneaonudspehmaissesiaoreneletracaktnredosonmpinla.tSceteriamwcuittlshaotweuidtthienamtneiosratshcioetniroptnahwkoeittoshnpo.ltahceerwphhoetnotnhse, eanxcdittehde

references

https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.
https://sites.google.com/a/coe.edu/principles-of-structural-chemistry/relationship-between-light-and-
matter/emission-and-absorption
https://www.fiberlabs.com/glossary/stimulated-emission
https://www.britannica.com/science/Stokes-lines