Chemical and Physical Changes

Label the following as either a chemical change or a physical change. The picture shows logs burning with bright flames.

a

b

Heating

Chemical Change

Freezing

Burning

Melting

Physical Change

Between chemical changes and physical changes, which type is often reversible but not always?

(a)  

I am found all around you. Sometimes I undergo phase changes such as from a solid to a liquid. Who am I?

• Steam

• Chemical change

• Matter

• Photosynthesis

Label each property as describing a chemical change or a physical change.

• Physical change

• Chopping

• Chemical change

• Shredding

• Chemical change

• Rusting

• Physical change

• Melting

• Physical change

• Digesting

Look at the sequence: How it starts—logs; Decide if heating or cooling—fire heating; How it ends—charred wood and ash. Was this a physical or chemical change, and is it reversible or irreversible?