This is about particulate model of matter this will teach you how to know what is solid,liquid and gases.It will also teach you about freezing,condasation and evapouration.It will be easier for you to understand and learn more about particulate model of matter.Let me explain more about what is particulate model of matter,solid is a hard object ,liquid and gases are a soft object.Solid has a fixed shape,volume and cannot be compressible it balanced forces which hold molecules in fixed position,they are arranged close together in a regular pattern and vibrate about fixed position when heated solid molecules gain energy and vibrate more,liquid has no fixed shaped but can flow and take its shape of container,it has fixed volume and also cannot be compressible and molecules are not held in fixed postition and move among one another throughout liquid and vibrate to and fro when heated liquid molecules vibrate and move about more vigorously,gases has no fixed volume,it can flow and spread easily and negligible and move randomly with high speed when heated gas molecules move even more randomly with higher speed.