Physical Science Glossary

acceleration … the rate in which the the velocity changes

balanced force … equal force acting on a object in different directions.

Centripetal Force … a force that causes an object to move in a cycle

energy … (physics) the capacity of a physical system to do work

force … push or pull on an object

free fall … when the only force acting on an object is gravity

friction … the force between two rubbing surfaces

gravity … the force that pulls objects towards each other

inertia : Newton’s first law of motion … an object in motion stays in motion

kinetic energy … the mechanical energy that a body has by virtue of its motion

Law of Conservation of energy … the law that states that energy cannot be created or destroyed but can be changed from one form to another

metalloid … an element that shares some properties with metal and some with nonmetals. also called semimetals

meter … a basic SI unit of length

molecule … neutral particle formed when atoms share electrons

natural law … a rule that describes an action or set of actions in the universe and that can sometimes be expressed as a mathematical statement

noble gas … elements in group 18 of the periodic table

nonmetals … gasses or brittle solids at room temperature and poor conductors of heat and electricity

objective … describes evidence that documents only what actually happened as exactly as possible

period … a row of elements in the periodic table whose chemical and physical properties change gradually and predictably

polar bond … bond resulting from the unequal sharing of electrons

precision … describes how close together or reproducible repeated measurements are

procedure … a collection of all the techniques that you use to do an experiment

prototype … a working model of a design that can be tested to see if it works

repeatable … describes evidence that can be seen independently by others if the repeat the same experiment or observation in the same way.

representative elements … elements in groups 1 and 2 and 13-18 in the periodic table that include metals, metalloids, and nonmetals

resolution … refers to the smallest interval that can be measured

scatterplot … a graph of 2 variables thought to be related

scientific method … a process of learning that begins with a hypothesis and proceeds to prove or change the hypothesis by comparing it with scientific evidence

semiconductor … elements that does not conduct electricity as well as a metal but conducts it better than a nonmetal

si … international system of units used by most countries for everyday measurements and used by the scientific community worldwide

significant difference … two results are only significantly different if their difference is much larger than the estimated error

significant digits … meaningful digits in a measured quantity

system … a group of variables that are related.

technology … the application of science to meet human needs and solve problems

theory … a scientific explanation supported by a lot of evidence collected over a long period of time.

transition elements … elements in groups 3-12 in the periodic table, all of which are metals

trial … each time an experiment is tried

unit … a fixed amount of something, like a cm of distance

variable … a factor that affects how an experiment works

volume … the amount of space taken up by matter

weight … a measure of the pulling force of gravity