PROPERTIES OF MATTERPg. 22

Physical Properties

Characteristics observed that don’t change identity

Physical properties help identify substances

Measuring Physical Properties Melting point- substance changes

from a solid to a liquid. Boiling point- substance changes

from a liquid to a gas Others: strength, hardness,

magnetism, ability to conduct electricity, density

Chemical Properties

Describes how a substance changes into a new substance

Can happen by combining with other elements or breaking down

Generally not easy to observe

Examples of Chemical Properties

Flammability –the ability to burn Reactivity-the capability of a substance

to combine with another substance Ex. Iron combining with oxygen

CHANGES OF MATTER

Physical Changes

Affects physical properties of a substance without changing the identity of a substance. Ex. melting, cutting, crushing, dissolving

Chemical Change

When one or more substances are changed into entirely new substances that have different properties Ex. a battery dying, leaves changing colors,

rust Chemical changes can not be reversed

by physical changes! Ex. Unbaking food

Clues for chemical changes Odor Change in color Fizzing or foaming Production of sound, light, or heat Production of a solid (called a

precipitate)

Which is which?

Identify which changes are physical and which are chemical