The state of matter which has no definite shape or volume is called ?
Gas
Temperature at which a liquid substance changes in a solid at atmospheric pressure is called freezing point .
water is a matter because it ocuppy space and has mass.
At atmospheric pressure the temperature at which a liquid boils and changes rapidly into a gas is called boiling point.
At one atmospheric pressure the temperature at which a solid sustances melts and changes into a liquid is called melting point.