Element
A substance made up of one type of atom
Molecule
A particle made up of two or more atoms that are joined together chemically
Compound
Made up of different kinds of atoms chemically combined
Mixture
Contains a variety of elements and compounds that are not chemically combined with each other
Two hydrogen atoms and one oxygen atom forms a what?
A water molecule
Pure substance
Has definite physical and chemical properties such as appearance, melting point, and reactivity.
Solid
A substance with a definite volume and shape. Particles are close together and locked in place with very little space to move
True or False: All matter is made of atoms that are in constant motion
True. Even solids are filled with atoms that are in motion.
Liquid
A substance with definite volume, but not a definite shape. Particles are close together and can slide past each other
Gas
A substance without a definite volume or a definite shape. Particles are far apart and can move freely
Which substance's atoms have the most kinetic energy? Solid, liquid, or gas
Gas, because the particles have so much space to move, that they move around at high speeds.
When a substance changes states, what happens to their particles?
The motion of their particles change
What is the result of melting?
A solid becomes a liquid
What is the result of freezing?
A liquid becomes a solid
What is the result of evaporation?
A liquid becomes a gas
What is the result of condensation?
A gas becomes a liquid
What is the result of sublimation?
A solid becomes a gas
What is the result of deposition?
A gas becomes a solid
True or False: Mass changes when a change of state occurs.
False: Mass is conserved when a change of state occurs. Example: When an ice cube melts from a solid to a liquid, there is the same amount of water molecules present in both the solid state and the liquid state.