the study of matter, the changes it undergoes and the energy required to change matter


any substance; has mass and volume


The quantity of matter contained in a body; measured in grams


measure of space that matter takes up; mL, cm3


A measure of force with which gravity pulls a body toward the center of the earth;


any part of a system with uniform composition and properties; a state

physical property

a quality or condition of a substance that can be observed or measured without changing the substance's composition

physical constant

properties of pure substances that can be measured and expressed numerically; fp, mp, d, etc.


the amount of mass in a given volume

physical change

one in which the form or appearance of matter changes, but not its composition

chemical properties

characteristic that cannot be observed without altering the substance

chemical change

a change that produces matter with a different composition than the original matter


smallest particle of an element

law of conservation of mass

Mass is neither destroyed nor created during ordinary chemical reactions or physical changes


a pure substance made of only one kind of atom


a substance formed by the chemical combination of two or more elements in definite proportions


A combination of two or more substances that are not chemically combined


uniform; of the same kind


not uniform throughout


capacity to do work or cause change


amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius


the SI unit of energy

potential energy

energy stored due to an object's position or arrangement

kinetic energy

the energy an object has due to 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


the total amount of kinetic energy due to molecular motion in a body of matter


a measure of the average kinetic energy of the particles in a sample of matter

heat of fusion

the amount of energy required to change 1 g of a solid to a liquid

heat of vaporization

the amount of heat energy required to convert one gram of a substance from a liquid to a gas


a device used to measure the heat absorbed or released in a chemical or physical change

exothermic reaction

a reaction that releases energy in the form of heat

endothermic reaction

A reaction that ABSORBS energy in the form of heat

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