PHYSICAL SCIENCE VOCABULARY - Lancaster High School

PHYSICAL SCIENCE VOCABULARY

acceleration- The rate of change in atomic nucleus; has a charge of 2+, an
velocity (a change in direction or a atomic mass of 4, and is the largest,
change in speed). slowest, and least penetrating form of
acid- A substance that produces radiation.
hydrogen ions in solution; these amalgam- An alloy containing the
solutions have a pH less than 7. element mercury; an example is dental
alternating current (AC) - Electric fillings.
current that reverses its direction in a ammeter- A galvanometer that
regular pattern; the 60-Hz AC in our measures electrical current passing
homes changes direction 120 times each through in amperes; connected in a
second. series with the circuit.
acid rain - Rain with a pH less than 5.6; amorphous- Something that has no
produced by substances in the air specific shape; for example, a liquid or
reacting with rainwater. gas.
acoustics -The study of sound. ampere -The unit of measuring current,
actinide- Any of the 14 radioactive the rate of flow of electrons in a circuit.
elements having atomic numbers 90- amplification- The process of increasing
103; used in nuclear power generation the strength of an electric signal.
and nuclear weapons. amplitude- In a wave, the distance from
active solar heating - Collecting the the rest position of the medium to either
sun's energy with solar panels, heating the crest or trough.
water with that energy, and storing the amplitude modulated - (AM) waves -
heated water to use the energy later. Radio waves whose amplitude is varied
aerosol -A liquid sprayed from a with voice, music, video, or data for
pressurized container; for example, a can transmission over long distances.
of insect spray. angle of incidence - In waves, the angle
air resistance - Frictional force air formed by the incident wave and the
exerts on a moving object; acts opposite normal.
in direction to the object's motion. angle of reflection - In waves, the angle
alchemist -A medieval version of the formed by the reflected wave and the
modern chemist; a practitioner who normal (perpendicular).
blended primitive chemistry with magic, anhydrous- A chemical compound that
seeking to turn ordinary metals into normally has water molecules attached
gold. to its ions but from which water has been
alcohol -Type of compound formed removed.
when -OH groups replace one or more antacid -An "anti-acid," or a chemical
hydrogen atoms in a hydrocarbon. that changes an acid substance to a
allotropes -Different structural forms of neutral substance.
the same element; for example, some antifreeze -A solute added to a solvent
carbon molecules form soft graphite, to lower the temperature at which the
whereas others form hard diamonds. solvent will freeze.
alloy -A mixture consisting of a metal aqueous -Describes a solution made
and one or more elements. with water.
alpha particle - A particle of nuclear
radiation emitted from a decaying

PHYSICAL SCIENCE VOCABULARY

Archimedes' principle - This Greek beta particle - A negatively charged
mathematician stated that the buoyant electron or positively charged positron
force on an object in a fluid is equal to emitted from a decaying atomic nucleus.
the weight of the fluid displaced by the binary compound - A chemical
object. compound composed of two elements;
aromatic compounds - Chemical for example, sodium chloride.
compounds that contain the benzene ring biogas Mixture of gases, mostly
structure; most have distinctive odors. methane, produced when biomass is
artificial satellite - Human-made device allowed to rot in the absence of air.
that orbits Earth; used for biomass -Organic material from such
communication, weather-monitoring, sources as wood, corn, and wastes from
military, and scientific purposes. animals and crops.
atomic number - The number of bionics The science of designing
protons in an atom's nucleus. artificial replacements for parts of the
average speed - A rate of motion human body that are not working
determined by dividing the total distance properly.
traveled by the total travel time. boiling point - The
average atomic mass - The average temperature at which vapor
mass of the mixture of an element's bubbles form in a liquid and
isotopes. rise to the surface,
balance -A device used in laboratories increasing evaporation.
to measure mass; it works by balancing a Boyle's law - British
mass to be determined with a standard scientist Robert Boyle
mass that is known. stated that volume of a gas decreases
balanced chemical equation - A when the pressure increases, provided
chemical equation that has the same the temperature stays the same.
number of atoms of each element on bubble chamber - Device filled with
both sides of the equation. superheated liquid; used to detect and
balanced forces - Forces that are equal monitor the path of charged nuclear
in size and opposite in direction. particles, which leave a trail of bubbles
bar graph - A type of graph used to as they pass though the chamber.
show information collected buoyant force - Ability of a fluid to
by counting; uses vertical or exert an upward force on an object
horizontal bars of different immersed in the fluid.
lengths to help people butane -A flammable gas; part of
compare quantities. natural gas.
base -A substance that byte -A basic unit of computer memory
produces hydroxide ions (OH-) in the represents a character (number,
solution; these solutions have a pH symbol, or alphabet letter); consists of 8
over 7. bits.
Bernoulli's principle - The Swiss calorimeter- An instrument used to
scientist Daniel Bernoulli stated that as measure changes in thermal energy.
the velocity of a fluid increases, the carbohydrate An organic compound
pressure exerted by the fluid decreases. having twice as many hydrogen atoms as
oxygen atoms.

PHYSICAL SCIENCE VOCABULARY

carbon 14 dating - Age-determining which elements are in a compound and
method for carbon-containing objects up their ratios.
to 50,000 years old. chemical property - A characteristic of
catalyst-A substance that speeds a a substance that indicates whether it can
chemical reaction without itself being undergo a specific chemical change.
permanently changed. chemical reaction - A change in which
cathode ray tube (CRT) - Sealed glass one or more substances are converted to
vacuum tube that uses electrons and different substances.
fluorescent material to produce images chemical symbol - A shorthand way to
on a screen. write the name of an element; for
central processing unit - The main example: C for carbon, Ag for silver.
circuit board inside a chemically stable - Describes an atom
computer that performs the whose outer energy level is completely
calculating and holds the filled with electrons.
main memory. chemically unstable - Describes an
centripetal acceleration - atom whose outer-most energy level is
Acceleration toward the not filled with electrons so it seeks
center of a circle by an object moving electrons from other atoms and thus
along a circular path. forms compounds.
centripetal force - The force that causes chloro Prefix that indicates presence of
an object moving along a circular path to chlorine, as in tetrachloroethylene or
move toward the center of the path. chlorofluorocarbon.
ceramic A material made from dried CFC A group of compounds whose
clay or claylike mixtures. decomposition releases chlorine atoms
cermet A tough, heat-resistant material that destroy ozone molecules in the
that has the properties of both a ceramic upper atmosphere.
and an alloy; ceramic-metal. circuit A closed path through which
chain reaction - A continuing series of electrons flow.
fission reactions in which neutrons from circuit breaker - A device that protects
fissioning nuclei cause other nuclei to an electrical circuit; if too much current
split, releasing more neutrons, which flows, the device opens the circuit,
split more nuclei, and so on. stopping the current.
Charles's law - The volume of a gas cloud chamber - Device filled with
increases when temperature increases, water- or ethanol-saturated air; used to
provided the pressure stays the same. detect charged nuclear particles, which
chemical bond - The force that holds leave a trail as they pass through.
together the atoms in a compound; it coagulation Process that destroys
occurs because atoms of most elements colloid structure; can be used to reduce a
become more stable by losing, gaining, colloidal form of air pollution.
and sharing electrons. coal A rock formed of ancient decayed
chemical change - The plants; burned as a fossil fuel.
change of substances to coefficient In a chemical equation, the
different substances. number that represents the number of
chemical formula - A units of each substance taking part in a
precise statement that tells chemical reaction.

PHYSICAL SCIENCE VOCABULARY

coherent light - A beam of light in constant speed - Speed that does not
which all the electromagnetic waves change.
travel with the crests and troughs contraction Movement of molecules
aligned; thus, the beam does not spread toward one another, so that they occupy
out. a smaller space.
colloid A heterogeneous mixture combustion Rapid burning.
containing tiny particles that never settle composite A mixture of two materials,
out; for example, milk and gelatin. one of which is embedded in the other.
compression In compressional waves, compound Substance made of the
the dense area of the wave. combined atoms of two or more
compressional wave - A type of wave elements.
where matter vibrates in the same compound machine - A combination of
direction the wave travels. two or more simple machines.
computer A device you can program to constant In an experiment, a factor that
do calculations, make logical decisions, does not change.
and manipulate data. control In an experiment, a standard for
computer virus - Type of program comparison that is often needed to draw
designed to infect a computer, erase a meaningful conclusion.
data, scramble other programs, or fill up convection The transfer of energy by the
so much memory that the system is bulk movement of matter in which
harmed. particles move from place to place in
concave lenses - Lenses that are thinner fluid, carrying the energy with them.
in the middle and thicker at the edges convex lenses - Lenses that are thicker
and thus curve inward; form virtual, in the middle than at the edges; can
upright, smaller images of an object. produce both real and virtual images.
concave mirror - A mirror whose convex mirror - A mirror with a surface
surface curves inward; produces real that curves outward; produces upright,
images. smaller, virtual images of an object.
concentrated solution - A solution in corrosive Hazardous compound that
which the amount of solute is near the attacks and alters metals, human tissue,
maximum the solvent can hold at that or other materials; for example, oven
temperature. cleaners and battery acid.
concentration Generally, the proportion coulomb The charge carried by 6.24
of a solute dissolved in a solvent. billion billion electrons.
condensation The change of a substance covalent bond - A type of chemical
from a gas to a liquid, which usually bond formed by atoms when they share
takes place when a gas is cooled to or electrons.
below its boiling point. crest The highest point of a wave.
condense To go from the gas state to the critical temperature - In
liquid state, due to a loss of heat. superconductors, the very low
conduction The transfer of energy temperature at which a material ceases to
through matter in which energy moves have any electrical resistance.
from particle to particle. crystals In most solids, the arrangements
conductor A material that allows of particles in repeating geometric
electrons to move easily through it. patterns.

PHYSICAL SCIENCE VOCABULARY

current The flow of electrons through a diode A type of rectifier that allows
wire or any conductor; measured in electric current to flow in only one
amperes with an ammeter. direction.
deceleration The rate of change in direct current - Electrical current that
velocity (speed and/or direction) when flows in only one direction through a
velocity is decreasing; also called wire.
negative acceleration. disinfectant A chemical that kills
decibel The unit of measure for sound bacteria, such as alcohol.
intensity, abbreviated dB. dissociation – The breaking apart of an
decomposition reaction - A chemical ionic compound into positive and
reaction in which a substance breaks negative ions when dissolved in water.
down into two or more simpler doping Adding an impurity to a
substances. semiconductor to increase its electrical
dehydrating agent - A substance that conductivity.
can remove water from materials. Doppler effect - An increase or decrease
density The mass per unit volume of a in wave frequency, caused by motion of
material; describes how tightly packed a the source and/or motion of the observer;
substance's molecules are. applies to all waves.
dependent variable - In an experiment, dot diagram - A diagram to represent
the factor whose value changes because electrons in the outer energy level of an
of a change in the independent variable. atom; uses the element symbols and
derived - Unit of measurement obtained dots.
by combining SI units. double displacement reaction - A
detergent An organic salt similar to chemical reaction in which two ionic
soap, except that detergents do not form compounds in solution react, forming a
soap scum in hard water. precipitate, gas, or water.
diatomic molecule - A molecule dry cell - A power source that acts as an
composed of two atoms of the same electron pump and generates electric
element. current by a chemical reaction; uses
diesel engine - An internal combustion thick, pasty electrolyte.
engine that compresses a fuel-air ductile – ability of metals to be pulled
mixture so much that it ignites from the into wires
heat of compression without a spark. effort arm - The part of a lever on
diffraction The bending of waves which an effort force is applied.
around a barrier. effort force - The force applied to a
diffraction grating - A piece of glass or machine when a machine is used to do
plastic with many parallel slits that acts work.
like a prism, causing white light that electric field - An area surrounding an
passes through it to separate into its electron that exerts a force on anything
component colors. nearby with an electric charge; strongest
dilute solution - A solution in which the nearest the electron and weakens with
amount of solute is much less than the distance.
maximum the solvent can hold at that electric motor - A device that contains a
temperature. rotating electromagnet that changes
electrical energy to mechanical energy.

PHYSICAL SCIENCE VOCABULARY

electrical power - The rate at which evaporation The gradual change of a
electrical energy is converted to another substance from a liquid to a gas at
form of energy; electrical power is temperatures below the boiling point.
expressed in watts or kilowatts. exothermic reaction - A chemical
electrolyte A substance that separates or reaction in which energy is released.
forms ions in a water solution, making Outward movement of molecules away
the solution an electrical conductor. from one another so that they occupy a
electromagnet Strong temporary larger space.
magnet made by inserting an iron core expansion combustion engine - An
into a wire coil and passing an electric engine in which the fuel is burned
current through the coil. outside the engine.
electromagnetic induction - Process by experiment An organized procedure for
which electrical current is induced in a testing a hypothesis; typically has a
wire when it is moved through a control and dependent and independent
magnetic field. variables.
electromagnetic radiation - Transverse farsighted Describes a person who sees
waves that transfer energy by radiation; faraway things clearly, but has trouble
vary in length from very long radio focusing on nearby objects.
waves to extremely short gamma waves. fiberglass Hairlike strands of glass that
electron arrangement - In an atom, make a good insulator when arranged in
how the electrons are distributed in the puffy layers.
atom's various energy levels. filter In working with light, a device that
electron cloud - Region where electrons allows one or more colors to be
most probably are found surrounding the transmitted while others are absorbed or
nucleus of an atom. blocked.
electrons Negatively charged particles flammable A chemical characteristic of
that move around the nucleus of an a substance that allows it to oxidize
atom. rapidly.
electroscope A device containing two fluid Any material that flows, such as
suspended metal leaves in a jar that liquids and gases.
move apart when charged; used to detect fluorescence Occurs when a material
the presence of electric charges. absorbs ultraviolet radiation that
element Substance in which all the stimulates it to radiate visible light.
atoms in a sample are alike. fluorescent light - Light produced when
endothermic reaction - A chemical ultraviolet radiation inside a fluorescent
reaction in which energy is absorbed. light bulb causes its fluorescent coating
energy The ability to cause change. to glow.
energy farming - The growing of plants focal length - The distance from the
for use as fuel. center of a lens or mirror to its focal
energy transfer - The movement of point.
energy from one object to another; for focal point - A point on the optical axis
example, thermal energy flowing as heat of a concave mirror or convex lens
from a heated stove to a skillet. where the light rays come together.
ester An organic compound formed by force A push or pull one body exerts on
reacting an organic acid with an alcohol. another.

PHYSICAL SCIENCE VOCABULARY

fractional distillation - A process based gasoline, but whose production may be
on boiling points used in oil refineries to damaging to the environment; a biomass
separate the chemical compounds in fuel.
crude oil into gasoline, kerosene, and gear A wheel with teeth around its edge
other products. designed to mesh with teeth on another
fractionating towers - Towers at oil gear so as to transfer force and motion.
refineries used for fractional distillation gelatin A substance obtained by boiling
of petroleum. animal bones; used in glues and goods.
free fall - How an object moves in space generator A device that uses
when it is influenced only by gravity. electromagnetic induction to induce
freon A refrigerant gas used in electrical current by rotating loops of
refrigerators and air conditioners. wire through a magnetic field.
frequency The number of wave crests geothermal energy - Thermal energy
that pass a point during one second; source located far below Earth's crust.
expressed in hertz. glass A ceramic mixture with no regular
frequency modulated - Radio waves crystal structure.
whose frequency is varied with voice, graduated cylinder - A cylinder marked
music, video, or data for transmission with volume scale, used in laboratories
over long distances. for measuring liquid volumes.
friction The force that opposes motion graph A visual display of information or
between two surfaces that are touching data organized to help people interpret,
each other. understand, or quickly find information.
fuel rod - A metal rod filled with graphite A mineral made of carbon
uranium pellets, used as the fuel in a atoms arranged in layers that easily slide
nuclear reactor. past one another, forming a dry
fulcrum The fixed point around which a lubricant.
lever pivots. gravity Force exerted by every object in
fuse A device that protects an electrical the universe on every other object. The
circuit. amount of force depends on the masses
galvanometer An instrument used to of the objects and the distance between
detect electric currents. them.
gamma rays - High frequency grounded Electrically connected to
electromagnetic waves that travel at the Earth, either directly or through a wire or
speed of light, have no mass or charge, other metal object.
and are the most penetrating form of group In the periodic table, each of the
radiation. 18 vertical columns of elements; each
gamma rays - High frequency group is made up of elements with
electromagnetic waves that travel at the similar properties.
speed of light, have no mass or charge hacker A person who uses a computer
and are the most penetrating form of to break into other computer systems
radiation. without permission.
gaseous solution - A homogeneous gas half life - The amount of time required
that is composed of two or more gases. for one-half of the nuclides in a sample
gasohol A mixture of ethanol and of radioactive isotope to decay.
gasoline that is a useful substitute for

PHYSICAL SCIENCE VOCABULARY

halogens Highly active elements in inclined plane - A simple machine
periodic table Group 17; they have seven consisting of a sloping surface used to
electrons in their outer shells and readily raise objects.
combine with Group 1 elements. incoherent light - Light rays that are
heat Thermal energy that flows from a nearly parallel, but spread out because
warmer material to a cooler material. their electromagnetic waves do not
heat engine - A device that converts travel in the same direction.
thermal energy that is produced by ideal machine - A machine in which
burning fuel into mechanical energy. work input equals work output; such a
heat mover - A device that moves perfect machine would be frictionless
thermal energy from one location and and 100 percent efficient
releases it in another location having a independent variable - In an
different temperature. experiment, the factor adjusted to a
heat of fusion - The amount of energy different value by the experimenter to
needed to change a material from the see what effect it will have on the
solid state to the liquid state. dependent variable.
heat of vaporization - The amount of indicator An organic compound that
energy needed to change a material from changes color in an acidic solution or a
a liquid to a gas. basic solution.
herbicide A chemical poison that kills induction Electrically charging an
undesirable plants. object or creating an electrical current in
hertz The unit of measure for frequency. it, without physically touching it.
heterogeneous mixture - A mixture in inertia The tendency of an object to
which different parts can be easily resist any change in its motion. If
distinguished. motionless, it tends to remain at rest; if
homogeneous mixture – A mixture in moving, it tends to keep moving at the
which different materials are blended same speed and in the same direction.
evenly so that the mixture is the same infrared radiation - Electromagnetic
throughout; also called a solution. waves that have a wavelength slightly
hydrate A compound that has water longer than visible light; indicates the
molecules chemically attached to its ions presence of heat.
and written into its formula. infrasonic waves - Waves at frequencies
hydraulic Describes a system operated below the limit of human hearing.
by the energy of moving water. inhibitor A substance that slows or
hydrocarbon A compound containing prohibits a chemical reaction.
only carbon and hydrogen atoms. instantaneous speed - The rate of
hydronium ion - The ion that makes a motion at a given instant in time.
solution acidic. insulator A material that does not allow
hypothesis A testable prediction used to heat or electrons to move through it
see how something works or to solve a easily.
problem. integrated circuit - A thin slice of
incandescent light - Light produced by silicon, often less than 1 cm on a side,
a thin tungsten wire, or filament, that is which can contain thousands of resistors,
heated in an incandescent bulb until it diodes, and transistors; used in computer
glows. and electronic equipment.

PHYSICAL SCIENCE VOCABULARY

intensity In sound waves, the amount of Law of conservation of mass - A law
energy in each wave. stating that matter is neither created nor
interference The ability of two or more destroyed during a chemical change.
waves to combine to form a new wave. Law of conservation of momentum - A
internal combustion engine - An law stating that the total momentum of a
engine in which fuel is burned inside the group of objects is conserved unless a
engine in chambers. net force acts on the objects.
ion A positively or negatively charge lever A simple machine consisting of a
atom. bar that is free to pivot around a fixed
ionic bond - A type of chemical bond point.
formed by the attraction between line graph - A type of graph used to
opposite charges of the ions in an ionic show trends or continuous change by
compound. drawing a line that connects data points.
ionization The breaking apart of certain lipids Fats, oils, and related organic
polar substances to form ions when compounds.
dissolved in water. liquid solution - A liquid solvent that
isomers Compounds that have identical has dissolved in it a gas, liquid, or solid.
chemical formulas but different liter The unit of liquid volume that
molecular structures and shapes. occupies the same volume as a cubic
isotopes Atoms of the same element that decimeter and is slightly larger than a
have different numbers of neutrons. quart.
joule The basic unit of energy and work. loudness The human perception of
kelvin The SI unit of temperature. sound intensity.
kilogram The SI unit of mass. lubricant A substance used to reduce
kilowatt hour - The unit of electrical friction between two surfaces that move
energy. together; for example, oil,
kinetic energy - Energy in the form of grease, or graphite.
motion, as in a moving car or truck. machine A device that
kinetic theory of matter - The idea that makes work easier by
all matter is made up of constantly changing the size of the
moving, tiny particles. force applied to it and/or the direction of
lanthanide Any of the 14 metallic the force.
elements having atomic numbers 58-71; magnetic bottle - A powerful magnetic
used in magnets, ceramics, and field that creates a container to hold the
television picture tubes. hydrogen plasma needed for a nuclear
laser A device that emits a beam of fusion reaction.
photons that travel in the same direction magnetic domains - Groups of atoms
and phase, producing a beam of coherent with aligned magnetic poles.
light. magnetic field - The region around a
Law of conservation of energy - A law magnet where magnetic forces act.
stating that energy can change form but magnetic poles - The two ends of a
cannot be created or destroyed under piece of magnetic material where the
ordinary conditions. magnetic forces are strongest, labeled
north pole and south pole.

PHYSICAL SCIENCE VOCABULARY

magnetism A property of some microscope A optical
materials in which there is a force of instrument that uses two
repulsion or attraction between certain convex lenses with
like and unlike poles. relatively short focal
magnifier A device that lengths to magnify small,
makes things appear larger so close-up objects.
that more detail can be seen; microwaves Radio waves with the
for example, a microscope. highest frequency and energy; used in
malleable Ability of metals to be communications and microwave ovens.
hammered or rolled into thin sheets. mixture A material made of elements or
mass A measurement of the amount of compounds stirred together but not
matter in an object. combined chemically.
mass number - Sum of the number of model A symbolic representation of an
protons and neutrons in an atom's idea, system, or structure to make
nucleus. something understandable.
mechanical advantage - The number of modulation Process of adding voice,
times a machine multiples the effort music, video, computer information, or
force applied to it. other data to radio waves by using
mechanical energy - The total amount electrical currents to vary either
of kinetic energy and potential energy in amplitude or frequency.
a system. momentum A property of any moving
medium A material through which a object; the product of an object's mass
wave travels. and velocity.
melt The changing of a substance from a monomers Organic molecules that are
solid state to a liquid state when heated strung together to form polymers.
above the substance's freezing/melting music Sound created using specific
point. pitches, sound quality, and regular
melting point - The temperature at patterns.
which a solid changes to a liquid. nearsighted Describes a person who
metallic bonding - The type of chemical sees nearby things clearly, but has
bond in which positively charged ions trouble focusing on distant objects.
are surrounded by freely moving net force - The sum of the forces on an
electrons. object when unbalanced forces are
metalloids Elements having properties applied to it.
of both metals and nonmetals. neutralization A chemical reaction
metals Elements usually having these between an acid and a base.
common properties: shiny, good neutralize To change an acidic solution
conductors of heat and electricity, are or a basic solution so that it is neutral.
solids at room temperature. neutron Atomic particle with no charge
meter The SI base unit of length. that is part of an atom's nucleus.
microprocessor The computer's "brain." Newton's first law of motion -
It receives input and tells the computer Describes the relationship between
how to respond. velocity and forces. An object moving at
a constant velocity keeps moving at that
velocity unless a net force acts on it.

PHYSICAL SCIENCE VOCABULARY

Newton's second law of motion - medicine, and so on; storing it is a
Describes the acceleration of an object in political and environmental problem.
the direction of the net force applied to nucleic acid - An organic polymer that
it. controls the activities and reproduction
Newton's third law of motion - of cells.
Describes action-reaction pairs; for nucleus The positively charged center of
every action force, there is an equal and an atom that contains protons and
opposite reaction force. neutrons.
NIMBY Not in my backyard; a point of nuclide The nucleus of a specific isotope
view that supports an issue such as having a certain specific atomic number
nuclear generation of electricity as long and atomic mass.
as it does not take place close to home. observation Using your senses to gather
noise Sound that has no regular pattern information.
or definite pitch. ocean thermal energy conversion -
nonelectrolyte A substance, such as Process that uses heat engines to convert
pure water, that does not conduct differences in ocean temperatures into
electricity. mechanical energy to drive turbines.
nonmetals Elements that usually are ohm The unit for measuring resistance.
gases or brittle solids at room Ohm's law - States that potential
temperature; most do not conduct heat or difference equals current multiplied by
electricity well. resistance.
nonpolar molecule - A molecule that opaque materials - Materials you can't
does not have oppositely charged ends. see through because they absorb or
nonrenewable resources - Resources reflect all light.
such as coal, oil, and natural gas, which Optical axis - A line perpendicular to
cannot be replaced after they are used the center of a mirror or lens.
up. optical fiber - Transparent glass fiber
normal In the study of light, an that can transmit light from one place to
imaginary line drawn perpendicular to a another.
reflecting surface or perpendicular to a organic compounds - Chemical
medium that light is entering. compounds that contain the element
nuclear fission - Process in which an carbon.
atom's nucleus is split into two nuclei organic solvent - A type of liquid often
with smaller masses. found in building materials; contains
nuclear fusion - Process in which two potentially harmful chemicals.
atomic nuclei with low masses are fused oxidation number - A positive or
into a single nucleus of larger mass; also negative number that indicates how
known as a thermonuclear reaction. many electrons an atom has lost, gained,
nuclear reactor - A device that or shared when bonding with other
generates electricity from a controlled atoms.
nuclear fission chain reaction. parallel circuit - An electrical circuit
nuclear waste - where the current flows through more
Radioactive by-products than one path. If one path is interrupted,
from nuclear power current will still flow through the other
generation, nuclear paths.

PHYSICAL SCIENCE VOCABULARY

pascal The SI unit of pressure. pitch The highness or lowness of a sound,
Pascal's principle - French scientist Blaise which is determined by the frequency of the
Pascal stated that pressure applied to fluid is sound waves.
transmitted unchanged through the fluid. plane mirror - A mirror with a flat surface
passive solar heating - Direct use of the that produces a virtual image.
sun's energy to heat something, without plankton Tiny plants and animals that live
using fans or mechanical devices to transfer in water and are food for small fish; they are
heat from one area to another. easily killed by acid rain.
period A horizontal row in the periodic plasma A gaslike mixture of charged
table. particles that exists at extremely high
periodic table - A table of the elements temperatures.
arranged according to repeated changes in plastic polymer-based material that can be
properties. easily molded.
PET Scans that are used in medicine to polar molecule - A molecule with opposite
reveal brain function and certain brain charges on each end.
disorders such as tumors. polarized light - Light in which the
petroleum Crude oil, formed by decayed transverse waves vibrate only along one
remains of plants and animals; a fossil fuel plane.
that is burned and used to make lubricants polarizing filter - A filter made of chains of
and plastics. molecules in parallel rows that will transmit
pH A measure of hydronium ion only light waves vibrating in the same
concentration in solution. direction as the molecular chains.
phenolphthalein A chemical used as a color polluted water - Water that contains high
indicator in titration; colorless in an acidic levels of unwanted substances that may be
solution, but turns pink in a basic solution. harmful to living things.
photon A tiny particlelike bundle of polyatomic ion - A group of covalently
radiation. bonded atoms in which the whole group is
photovoltaic cell - A device used to convert positively or negatively charged.
solar energy directly into electrical energy; polymer A huge molecule made up of many
also called a solar cell. smaller organic molecules, called
physical change - A change in the size, monomers, that have formed new bonds and
shape, color, or state of matter. are linked together.
Physical property - Any characteristic of a positron A positively charged particle
material that can be observed without similar to an electron.
changing the identity of the material itself. potential difference - The difference in
physical science - The study of matter and electric potential energy between two
energy; topics for study include chemistry different points; measured in volts.
and physics. potential energy - Stored energy.
pickling A process that removes impurities power The measure of the amount of work
from the surfaces of steel and other metals done in a specific amount of time.
by dipping them in hydrochloric acid. precipitate An insoluble compound formed
pigment Colored material that absorbs some during a double-displacement reaction.
colors and reflects others; the colors of pressure The amount of force exerted per
pigments are determined by the colors they unit of area.
reflect.

PHYSICAL SCIENCE VOCABULARY

principle A basic rule or law describing rectifier Any device that converts
how something always works in the natural alternating current into direct current.
world. reflecting telescope - An optical instrument
products In a chemical reaction, the that uses a concave mirror, a plane mirror,
substances produced by the reaction. and a convex lens to magnify distant objects.
projectile Any object shot or thrown reflection Occurs when a wave strikes an
through the air. object and bounces off.
propane A flammable gas and a part of refracting telescope - An optical instrument
natural gas. that uses two convex lenses to magnify
protein Organic polymer formed from distant objects.
amino acids. refraction The bending of waves, caused by
proton Atomic particle with a positive changing their speed.
charge that is part of an atom's nucleus. resistance The opposition to the flow of
pulley A simple machine consisting of a electrons through a conductor; measured in
grooved wheel with a rope or a chain ohms.
running along the groove. resistance arm - The part of a lever that
quality In sound, the difference among exerts the resistance force.
sounds of the same pitch and loudness. resistance force - The force exerted by a
quarks Very small particles of matter that machine to overcome resistance to gravity or
make up protons and neutrons; presently six friction.
different types are known. resonance The tendency of an object to
radiation The transfer of energy in the form vibrate at the same frequency as another
of waves. It is a type of energy transfer that vibrating source.
does not require matter. reverberation The echoing effect produced
radiator A device with a large surface area by multiple reflections of sound.
that transfers heat to surrounding air by RNA A nucleic acid that controls production
conduction. of proteins that make new cells.
radio waves - Electromagnetic waves that ROM In a computer, it is permanent
have long wavelengths and are used in memory stored inside the computer, even
communications. when the power is turned off.
radioactive element - An unstable element salt A compound formed during a
whose nucleus brakes down and gives off neutralization reaction when negative ions
particles, radiation, and energy. from an acid combine with positive ions
radioactivity The emission of high-energy from a base.
radiation or particles from the nucleus of a saponification The process of making soap.
radioactive atom. saturated hydrocarbon - A hydrocarbon
RAM In a computer, temporary memory that contains only single-bonded carbon
that is lost when the computer is turned off. atoms; an example is propane.
rarefaction In compressional waves, the saturated solution - A solution that has
less dense area of the wave. dissolved all the solute it can normally hold
reactants The starting substances in a at a specific temperature.
chemical reaction. scientific law - A rule that describes, but
real image - An image produced where light does not explain, a pattern in nature and
rays converge, as with a concave mirror or predicts what will happen under specific
convex lens. conditions.

PHYSICAL SCIENCE VOCABULARY

screw A simple machine consisting of a solution A homogeneous mixture containing
special type of inclined plane wrapped in a particles so tiny that they cannot be seen
spiral around a cylindrical post. even with a microscope.
second The SI unit for time. solvent The substance that dissolves a
semiconductor An element that conducts solute.
electricity under certain conditions. specific heat - The amount of energy
series circuit - An electrical circuit where needed to raise the temperature of 1 kg of
the current has only one path. If the path is material 1 K; it is measured in joules per
interrupted in any point, it stops current flow kilogram per kelvin.
in the entire circuit. speed The rate of motion, or the rate at
SI Standard, easy to use, worldwide system which a body changes position.
of measurement based on powers of ten. The standard In measurement, an exact quantity
standards are used by all scientists, and are a that everyone agrees to use as a basis of
modern version of the metric system. comparison.
simple machine - A device that state of matter - Any of the four conditions
accomplishes work with only one in which matter can exist: solid, liquid, gas,
movement. The lever, pulley, wheel and or plasma.
axle, inclined plane, screw, and wedge are static electricity - The net buildup of
all examples. electric charges on an object.
single displacement reaction - A chemical step down transformer - An electrical
reaction in which one element replaces transformer that decreases the voltage of a
another element in a compound. power line.
soap An organic salt made by reacting fats step up transformer - An electrical
or oils with a strong base such as sodium transformer that increases the voltage of a
hydroxide. power line.
solar collector - A strong acid - An acid that ionizes almost
device that absorbs completely in solution; for example,
radiant energy from hydrochloric acid and sulfuric acid.
the sun that can be strong base - A base that dissociates
converted to completely in solution; for example, sodium
thermal energy and hydroxide.
used to heat sublimation The process in which a solid
buildings. changes directly to a vapor without forming
solar energy - Energy from the sun. It is a liquid.
free and can be converted into thermal substance Matter that is an element or a
energy to heat homes and other buildings. compound.
solubility The amount of a substance that substituted hydrocarbon - A hydrocarbon
will dissolve in a solvent; generally in which one or more hydrogen atoms have
expressed as the maximum number of grams been replaced by atoms of other elements.
of solute that will dissolve in 100 g of a supercollider A device to make protons
solvent at a specific temperature. collide at high speed so they break apart into
solute The substance being dissolved in a quarks.
solvent.

PHYSICAL SCIENCE VOCABULARY

superconductor A supercooled material damage or destroy plants and animals that
that has no electrical resistance; a current live there.
can flow indefinitely through a thermonuclear fusion - Nuclear fusion that
superconductor without losing energy. occurs under conditions of
supersaturated solution - An unstable enormous heat, as in a star.
solution that contains more solute that a tidal energy - Energy produced
saturated solution can at that same specific by the rise and fall of ocean
temperature. levels; used to generate
suspension A heterogeneous mixture electricity.
containing a liquid in which larger particles time The interval between two events.
eventually settle out. titration Process in which a solution of
synthesis reaction - A chemical reaction in known concentration is used to determine
which two or more substances combine to the concentration of an acidic or basic
form a different substance. solution.
synthetic fiber - A thin strand of synthetic total internal reflection - Occurs when all
polymer that can be woven into fabrics; the light striking a surface between two
examples include nylon and Kevlar fibers. materials is reflected totally back into the
technology The practical use of scientific first material.
information to improve the quality of human toxic Hazardous
life. substance that can
telephoto lens - A lens having a long focal injure living tissue.
length and producing an enlarged, close-up tracer A radioisotope
image of an object. used in medical
temperature A measure of the average diagnosis to allow
kinetic energy of the particles that make up a doctors to monitor
sample of matter. human body functions, locate tumors, detect
terminal velocity - The greatest velocity fluid movement, and so on.
reached by a falling object. It is achieved transistor A semiconductor that amplifies
when the force of gravity is balanced by air or strengthens an electrical signal or acts as
resistance. a tiny off/on switch.
theory The most logical explanation of why transformer A device that
things work the way they do. A former can increase or decrease the
hypothesis that has been tested with repeated voltage of an alternating
experiments and observations and found current.
always to work. transition element - An
thermal energy - Total energy of a element in Groups 3-12 of
material's particles, including both kinetic the periodic table; typically, these are metals
energy and potential energy. with one or two electrons in their outer
thermal expansion - A characteristic of energy level.
almost all material that causes it to expand translucent materials - Materials that can
when heated and contract when cooled. be hazily seen through because they allow
thermal pollution - Pollution caused when some light to pass through them, but not
waste heat raises the temperature of the enough for a clear image.
environment. In bodies of water, it can

PHYSICAL SCIENCE VOCABULARY

transmutation- Changing one element to voltmeter -A galvanometer that measures
another through radioactive decay. potential differences in volts and is placed in
transparent materials - Materials that can parallel across a part of the circuit.
be clearly seen through because they allow Volume- The amount of space occupied by
light to pass through them. an object.
transuranium element - Any element wave -A rhythmic disturbance that carries
having more than 92 protons, the atomic energy through matter or space.
number of uranium. wavelength The distance between identical
transverse wave - A type of wave where the points on two adjacent waves; for example,
medium moves at right angles to the the distance between two crests or two
direction the wave is traveling. troughs.
trough The lowest point of a wave. weak acid - An acid that partially ionizes in
Tyndall effect - The scattering of light by solution; for example, carbonic acid.
particles in a mixture; this effect can be seen weak base - A base that partially dissociates
in all colloids. in solution; for example, magnesium
ultrasonic technology - Technology using hydroxide.
high-frequency sound waves for many Wedge- A simple machine consisting of a
different purposes such as medical moving inclined plane with one or two
diagnoses, sonar, and jewelry cleaning. sloping sides; examples are knives and
ultraviolet radiation - Electromagnetic chisels.
waves that have a higher frequency than weight -The measure of the force of gravity
visible light. of an object.
unsaturated hydrocarbons - Hydrocarbons wet cell - A power source that generates
that contain at least one double or triple electric current by a chemical reaction using
bond between carbon atoms. a liquid electrolyte.
unsaturated solution - A solution that is wheel and axle - A simple machine
capable of dissolving more solute at a consisting of two different-sized wheels that
specific temperature. rotate together, such as a doorknob.
velocity -The speed and direction of a wide angle lens - A lens with a short focal
moving body, such as a storm or a length that produces a relatively small image
basketball thrown across a court. of an object, but includes much of the
Venturi effect - Reduction in pressure of a object's surroundings.
fluid resulting from the speed increase as work -The transfer of energy through
fluids are forced to flow faster through motion.
narrow spaces. X rays - Electromagnetic waves having a
virtual image - An image formed of wavelength shorter than ultraviolet
diverging light rays, as in a plane or convex radiation; often used in medical diagnosis
mirror, or seen through a concave lens. and photography because they can penetrate
visible radiation - Electromagnetic waves human tissue.
in the only part of the electromagnetic
spectrum we can see--light.
volt The unit for measuring electrical
potential energy.
voltage A difference in electrical potential,
measured in volts with a voltmeter.