What is matter ? what are the states of matter?

What is matter ? what are the states of matter? 

"Any thing that has mass and occupies volume in space is known as matter."

Matter is made up of microscopic particles (now we call them molecules). These molecules posses kinetic energy and have inter-molecular forces (attraction & repulsion). These two factors of molecules decides the states of matter. 

On the earth matter is present in three states, as given below -

1. Gas

2. Liquid

3. Solids

What are properties of matter ? 

The macroscopic and microscopic properties of matter are given briefly in below table -

Property	State of matter
	Gas	Liquid	Solid	Remark
Macroscopic properties
Volume & shape	Gas does not have fixed volume or shape	Liquid has fixed volume but does not have fixed shape	Solids have fixed volume & shape	At fixed temperature and pressure
Density	Low	Medium	High	Exceptions are not rare eg. Ice has lower density than water
Effect of pressure	If pressure is applied to gases they turned to liquids	If pressure is applied to liquids they maintain the liquid state (liquids are non - compressible)	-	At fixed temperature
Effect of temperature	Gases expand with increase in temperature. Gas condense with decrease in temperature	Liquid vaporizes with increase in temperature. Liquid solidifies with decrease in temperature	Solid melts with increase in temperature.	At fixed pressure
Surface tension	Low	Medium	High	-
Microscopic properties
Order of molecular arrangement	Very low	Medium	Medium to High	-
Kinetic energy of molecules	Very high. The molecules are in random motion, speed past one another	Medium. The molecules are in random motion, skip one another	Low. The molecules can only vibrate at their fixed position.	-
Inter molecular force of attractions	Very low	Medium	High	-
Inter molecular spaces	Very high. The molecules are far apart from one another	Medium. The molecules have hardly any void spaces.	Low. The molecules are compactly arranged with respect to one another.	-