Question

what are the two external and internal factors which decide the state of matter

Answer 1

Here are the properties of different states of matter by which you can decide the state of matter.
Solid:
Fixed shape and Volume
Very small space between the particles.
Very large attraction between particles
Very low compressibility.
Very rigid.

Liquid:
Fixed volume but not fixed shape
Space between particles is larger than solids
Attraction between particles is smaller than solids.
Low compressibility.
Comparatively less rigid than solids.

Gas:
No fixed shape and volume.
Largest space between the particles.
Smallest attraction between the particles.
High compressibility.
Gases are not rigid.