S.NITYASRI (CHAPTER 8 RADIOACTIVE)

NAME : NITYASRI D/O SASSITHARAN
CLASS : 3 DLP
CHAPTER : RADIOACTIVITY
YEAR : 2022
SCHOOL NAME : SMK DATO’ ZULKIFLI MUHAMMAD
TEACHER’S NAME : MR.KUMAR

A ▪ Atoms originate from the word “ atomos “ which means indivisible.
▪ An atom is a particle of matter that uniquely defines a chemical
ATOM
element.
B
▪ Beta particles (β) are high energy, high speed electrons (β-) or
BETA protons (β+) that are ejected from the nucleus by some
radionuclides during a form of radioactive decay called beta-
C decay.

COSMIC RAY ▪ Cosmic rays are a form of high-energy radiation that
originate from outside our solar system.

D ❑ Radioactive substances can be used in the field of defence such as
the nuclear bomb.
DEFENCE Beside heat, radioactive released from the explosion of a nuclear
bomb destroys almost all living things including humans and its
E effect exists for generations.

ELECTRON ❑ Electron is a stable subtomic particles with a charge of negative
electricity.
F
❑ It can be seen in all atoms and acting as the primary carrier
FOOD PRESERVATION of electricity in solids.

❑ The Radura logo is used to lable food preserved using radioactive
radiation such as gamma rays.

❑ Gamma rays are used in the preservation of food such as fruits to
kill bacteria in the food.

G ✓ Gamma ray, electromagnetic radiation of the
shortest wavelength and highest energy.
GAMMA RAY
✓ Antoine Henri Becquerel was a French engineer, physicist, Noble
H laureate, and the first person to discover evidence of radioactivity. For
work in this field he, along with Marie Sklodowska-Curie and Pierre
HENRI BECQUEREL Curie, received the 1903 Nobel Prize in Physics.

I ✓ An ion is an atom or group of atoms that has an electric charge. Ions
with a positive charge are called cations. Ions with a negative
ION charge are called anions.

J ❖ In 1932,
Joliot Curie and her husband Frederic had full access to Marie’s
JOLIOT CURIE polonium. Experiments were done using gammas rays to identify
the position.
K
❖ Kilogram is S.I. unit of mass ( equivalent to appromaximately
KILOGRAM 2.2051b ), first introduced as a unit of mass metric system.

L ❖ Lead is a chemical element with the symbol Pb and atomic number 82.
It is a heavy metal that is denser than most common materials. Lead is
LEAD soft and malleable, and also has a relatively low melting point. When
freshly cut, lead is a shiny grey with a hint of blue. It tarnishes to a dull
grey color when exposed to air.

M o The MICROSievert is a unit in the International System of units
intended to represent the stochastic health risk of ionizing
MICROSIEVERT radiation.

N o A nuclear and radiation accident is defined by the International
Atomic Energy Agency as “an event that has led to significant
NUCLEAR ACCIDENT consequences to people, the environment of the facility.

P o Polonium is a radioactive chemical element (atomic number 84) that
was discovered in 1898 by Marie Curie, who named the element after
POLONIUM her country, Poland. In its natural state, at room temperature, polonium
is a solid metal with a silver color. Polonium-210 is one of 25 known
radioactive isotopes of polonium.

Q ➢ Quantity is amount of number of a material or abstract thing not
usually estimated by spatial measurement.
QUANTITY
➢ Radioactivity is a act of emitting radiation spontaneously.
R
➢ A spectrum is defined as the characteristic wavelengths of
RADIATION electromagnetic radiation ( or a portion thereof ) that is emitted
or absorbed by an object or substance, atom , or molecule.
S

SPECTRUM

T • Thorium is a weak radioactive metallic chemical
element with the symbol Th and atomic number 90.
THORIUM
• Uranium is a silvery-white metallic chemical element in the periodic
U table, with atomic number 92. It is assigned the chemical symbol U. A
uranium atom has 92 protons and 92 electrons, of which 6 are valence
URANIUM electrons. Uranium has the highest atomic weight of all naturally
occurring elements.

W • Wilhelm Conrad Röntgen was a German mechanical engineer and
physicist, who, on 8 November 1895, produced and detected
WILHELM CONRAD ROENTGEN electromagnetic radiation in a wavelength range known as X-rays
or Röntgen rays, an achievement that earned him the inaugural
Nobel Prize in Physics in 1901.

X ▪ X-rays are a form of electromagnetic radiation, similar to visible
light.
X-RAY
▪ Civil year the period of time, the calendar year,
Y containing 365 days or in a leap year 366 days.

YEAR