Science Test

Substance

type of matter with a fixed composition that can’t be separated by physical means

Element

substance made up of atoms with same identity

Mixture

materials made of two or more substances that can be separated by physical means

Homogeneous Mixture

mixture where 2 or more substances uniformly spread throughout

Heterogeneous Mixture

mixture where different materials can be easily distinguished

Physical Properties

characteristic of a material that you can observe without changing the substance

Chemical Properties

Characteristic of a substance that indicates whether it can undergo a certain chemical change

Physical Change

A change in size, shape, or state of matter; substance DOES NOT change identity when it undergoes physical change

Chemical Change

A change in one substance to another substance

Solid

Definite shape and definite volume

Liquid

Indefinite shape and definite volume

Gas

Indefinite shape and indefinite volume

Solid molecules

Closely packed in geometric arrangement

Liquid molecules

Have more space and slide past each other

Gas molecules

Have energy to spread out evenly in container

Heat

transfer of energy (how fast molecules moving)

Temperature

measure of around how fast atoms are moving

Melting

change from solid to liquid state

Melting Point

Temperature when a solid melts

Freezing

change from liquid to solid in state

Freezing point

temperature of when a solid melts

Vaporization

change from liquid to gas

Boiling point

temperature when liquid to gas

Evaporation

only happens on surface of liquid

Buoyancy

the ability of a fluid to go upward

Kinetic Molecular Theory (short answer)

All matter is composed of particles
Particles are in constant random motion
Particles collide with each other and walls of their container