Chemical and Physical Properties

Chemical and Physical Properties

All substances have properties that we can use to identify them. For example we can identify a person by their face, their voice, height, finger prints, DNA etc. The more of these properties that we can identify, the better we know the person. In a similar way matter has properties - and there are many of them. There are two basic types of properties that we can associate with matter. These properties are called Physical properties and Chemical properties:

Chemical Property:

Examples:

Physical Property:

Examples:

Label each as either a P (physical) or C (chemical) property:

___ Gasoline is flammable

___ Gold is malleable (can be hammered flat without breaking)

___ Bromine is a brown liquid

___ Alcohol has a boiling point of 89ºC

___ Copper tarnishes

___ Aluminum has a melting point of 660ºC

___ Sandpaper is rough

___ Diamonds are the hardest substance known to mankind

___ Silver is a good conductor of electricity

How can we recognize a change in chemical composition? What might we observe that tells us that a substance has changed into something else through a chemical reaction?

Label each as either a P (physical) or C (chemical) change:

___ Sugar dissolves in water

___ Milk sours

___ Sodium explodes in water

___ Water is heated and changes to steam

___ Pancakes cook on a griddle

___ Food is digested in the stomach

Which of the following is NOT a physical change?

a. grating cheese
b. melting cheese
c. fermenting of cheese
d. mixing two cheeses in a bowl

Which of the following would NOT be a physical change?

a. freezing water to make ice cubes
b. melting gold to make jewelry
c. burning gasoline in a lawnmower
d. boiling water for soup
e. tearing a piece of aluminum foil