A|B|C|D|E |F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W

A

Absolute Zero

• 0ƒK or -273.15ƒC. The temperature at which all molecular motion appears to be static (non-moving).

Acceleration

• The change of velocity over the change in time.

Adhesion

• The force of attraction between unlike molecules.

Amorphous

• A solid with randomly placed molecules.

Angstrom

• A unit of linear measure equal to 1 billionth of a meter.

Atom

• The smallest particle of an element that can exist either alone or in combination with other atoms of the same or other elements.

Atomic Number

• The number of protons in the nucleus of an atom.

Average Velocity

• Distance over a change in time.

B

Basic Equation

• An equation that expresses the solution to a problem in terms of usual defining quantities.

Beam

• Several parallel rays of light considered together.

Boiling Point

• The temperature at which the vapor pressure of a liquid equals the pressure of a liquid is equals the pressure of the atmosphere.

Brownian Movement

• The movement of molecules in a liquid.

C

Calorie

• The quantity of heat equal to 4.192 joules.

Candle

• The unit of luminous intensity of a light source.

Celcius Scale

• The temperature scale using the ice point as 0ƒ and the steam point as 100ƒ, with 100 equal divisions and degrees between; formerly the centigrade scale.

Centrifical Force

• Force that tends to move the particles of a rotating object away from the center of rotation.

Centripetal Force

• The force that produces an acceleration directed toward the center of a circular path.

Chemical Change

• A change in which new substances with new properties are formed.

Circular Motion

• Motion of a body along a circular (round) path.

Cohesion

• The force of attraction between like molecules

Concave

• Surface with center of curvature on the same side as the observer.

Concentric

• Having a common center. A circle within a circle within a circle.

Concave Lens

• A lens that splits light rays.

Concave Mirror

• A mirror that focuses light rays together.

Condensation

• The change of phase from a gas or vapor to a liquid.

Convex

• Surface with the center of curvature on the opposite side of the observer.

Convex Lens

• The lens that brings together parallel light rays.

Convex Mirror

• A mirror that splits light rays.

Critical Velocity

• Velocity needed to keep an object going in a circle.

Crystalline

• Matter with orderly arrangedmolecules.

D

Diffraction

• The spreading of a wave disturbance into a region behind and obstruction.

Diffusion

• The scattering of light by irregular reflection.
• The movement of a gas.

Displacement

• A change of position in a particular direction.

Ductility

• The property of a metal that enables it to be made into a wire.

E

Elastic

• The property of an object to return to its original size or shape.

Electron

• A negatively charged subatomic particle that revolves around the nucleus of an atom.

Emulsion

• A mixture of mutually insoluble liquids.

Energy

• A physical quantity that has the capacity of doing work.

Equilibrium

• The state of a body in which there is no change in its motion.

Evaporation

• The change of phase from a liquid to a gas or vapor.

F

Fission

• The splitting of a heavy nucleus into nuclei of medium mass.

Flux

• Flow.

Focus

• A point at which light rays meet or from which rays of light diverge.

Frame of Reference

• Any system for specifying the precise location of objects in space.

Freezing Point

• The temperature at which a liquid changes to a solid.

Frequency

• The number of crests of a wave that pass a point in a second.

Friction

• A force that resists the motion of objects.

Fusion

• A reaction in which like nuclei combine to form a nucleus with a larger mass number.

G

Gas

• Molecules that aren't closley packed and don't have any pattern.

Geometric

• A sequence in which the ratio of a term to its predecessor is always the same.

Graviton

• The carrier for the gravitational interaction.

Gravity

• The force of gravitation on an object on or near the surface of a celestial body.

H

Half-Life

• The length of time during which, half of a large number of radioactive nuclides decay.

Heat

• Thermal energy in the process of being added to, or removed from, a substance.

Hypothesis

• A plausible solution to a problem.

I

Ice Point

• The melting point of ice at STP.

Illumination

• The lighting up of a surface.

Image

• The optical counterpart of a figure formed by a lens or mirror.

Impulse

• The product of a force and the time interval during which it acts.

Inertia

• The property of matter that opposes any change in its state of motion.

Interface

• The boundary between two phases or systems.

Ion

• An atom or a group of atoms having an electric charge.

J

Joule

• Unit of work. The product of a force of one newton acting through a distance of one meter.

K

Kelvin Scale

• The scale of temperature having a single fixes point, the temperature of the triple point of water, which is assigned the value 273.16ƒK.

Kilocalorie

• Heat energy equivalent to 4190 joules; 1000 calories.

Kinetic Energy

• Energy due to the motion of an object.

L

LASER

• An acronym for Light Amplification by Stimulated Emission of Radiation.

Law

• A statement that describes a natural phenomenon; a principal.

Light Ray

• A directed line showing the direction of light.

Linear Accelerator

• A device for accelerating particles in a straight line through many stages of small potential difference.

Liquid

• Molecules that don't have a definite form, and aren't closely packed.

Lumen

• The unit of luminous flux; the luminous flux of a unit surface all points of which are the unit distance from a point source of one candle.

Luminous

• Visible because of the light emitted by its oscillating particles.

Luminous Flux

• The part of the total energy radiated per unit of time from a luminous source that is capable of producing the sensation of sight.

M

Machine

• A device that multiplies force at the expense of distance or that multiplies distance at the expense of force.

Magnetic Field

• The area around a magnet where it's magnetic force can be experienced

Malleability

• The property of a metal that enables it to be hammered or rolled into sheets.

Mass

• A measure of the quantity of matter; a fundamental physical quantity.

Matter

• Anything that has mass and takes up space.

Medium

• Any region through which a wave disturbance propogates.

Melting Point

• The temperature at which a solid changes to a liquid.

Meter

• A unit of length equal to 39 inches.

Mole

• Amount of substance containing the Avogadro number of particles such as atoms, molecules, ions, electrons etc.

Molecules

• The smallest particle of an element or compound capable of independent existence.

N

Neutron

• A neutral subatomic particle found in the nucleus.

Newton

• The force required to accelerate one kilogram of mass at the rate of one meter per second each second.

Normal

• A line drawn perpendicular to a line or surface.

Nuclear Binding Force

• The force that acts within the small distances between nucleons.

Nuclear Change

• A change in the identity of atomic nuclei.

Nucleon

• A proton or neutron in the nucleus of an atom.

Nucleus

• Positively charged dense central part of an atom.

P

Particle Accelerator

• A device for accelerating particles through many stages of small potential difference.

Perpendicular

• One line meeting another line at a right angle

Period

• The time for one complete cycle, vibration, revolution, or oscillation.

Phase

• A condition of matter.

Photon

• A quantum of light energy.

Physical Change

• The change of the appearance but not of its composition.

Power

• The time rate of doing work.

Pressure

• Force per unit area.

Property

• A measurable aspect of matter. For example, mass, inertia.

Proton

• A positively charged subatomic particle found in the nucleus.

Q

Quantum

• An elemental unit of energy; a photon of energy.

R

Real Image

• An image that is formed by actual rays of light.

Rectilinear Propagation

• Traveling in a straight line.

Reflection

• The return of a wave from the boundary of a medium.

Refraction

• The bending of a wave due to a change in the medium.

Resultant Force

• The single force that has the same effect as two or more forces applied at the same time at the same point.

S

Scientific Notation

• A positive number expressed in the form of M x10 raised to the n in which M is a number between 1 and 10 and n is an integral power of 10.

Second

• A unit of time equal to 1/60th of a minute.

Solid

• Molecules that are packed closley and have a definite form.

Solidification

• A change of phase from a liquid to a solid.

Speed

• The measure of how fast an object is moving.

Steam Point

• The boiling point of water at STP.

STP

• Standard temperature and pressure.

Sublimation

• The change of a solid to a gas.

Surface Tension

• The tendency of a liquid surface to contract.

T

Temperature

• The physical quantity that is proportional to the average kinetic energy or translation of particles in matter.

Tensile Strength

• The force required to break a rod or wire of unit cross
• sectional area.

Theory

• An idea that has not yet been proven.

Thermal Energy

• The total potential and kinetic energy associatd with the random motions of the particles of a material.

U

Ultraviolet Light

• Electromagnetic radiations of shorter wave length than visible light but longer than X rays.

V

Vapor

• The gaseous phase of a substance that exists as a liquid or solid under normal conditions.

Vaporization

• The change in phase from a solid or a liquid to a gas.

Vector Quantity

• Quantity that has both magnitude and direction.

Velocity

• Speed in a particular direction.

Vertex

• A center of a curved mirror.

Volume

• The amount of space occupied by a three-dimensial figure as measured in cubic units.

W

Watt

• A unit of power equal to one joule of work done in one second.

Wavelength

• Distance from crest to crest in the line of advance of a wave.

Weight

• The measure of the gravatational force on an object.

Work

• The application of a force moving an object a distance.