There are 3 states of matter:-

(i) Solid → It’s melting point is above room temperature under atmospheric pressure.

(ii) Liquid → It’s m.pt. is above soon temperature.

(iii) Gas → It’s b.pt. is below room temperature under atmospheric Pressure

→ The temperature at which all the these phases exist together is called Triple point

e.g. triple pt. of mater is 0.01^°C, & 4.58 mm pressure besides 3 states, of matter, 2 more states of matter exist (i) Plasma state which complains mixture of electrons and positively charged ions e.g. is sun & stars (ii) Super cooled solid is which atmosphere there identify & condense to form single super atmospheric.

One more state is also there known as

He – II → A liquid which behaves like gas

THE GASEOUS STATE

Characteristics of gas →

(i) Gases have neither definite shape nor definite volume & there take up the shape of container.

(ii) There are highly compressible because they have lots of inter particle space  

(iii) There show diffusion

(iv) There exert pressure equally in all directions