Air is different from a pebble and water because it does not

have a definite shape
have a definite volume
takes up space
have a mass

Which of the following is not a property of a gas?

cannot be compressed
no definite volume
no definite shape
flow easily

The following are examples of chemical change EXCEPT

burning woods
photosynthesis
hammered candies
rusting iron

It is the amount of matter in a given space.

weight
mass
force
volume