Ans : Matter :
Matter is defined as anything that has mass & occupy space.
States Of Matter :
There are three common states of matter they are : Solids , Liquids & gases.
Solid State :
Solid state of matter occupies a definite shape as well as definite volume.
Liquid State :
Liquid state of matter has a definite volume but does not occupy a definite shape. It takes the shape of the container in which it is kept.
Gaseous State :
Gaseous state of matter neither occupies a definite shape nor a definite volume. It takes the shape of the vessel in which it is kept & diffused into the space around it.