Question

Do we have to make changes every time in the temperature and pressuer to change the state of a matter? Explain.

Answer 1

Yes, we need to make changes every time in either Temperature or pressure to change state of matter.
EFFECT OF CHANGE OF TEMPERATURE ON MATTER:
On increasing the temperature of solids , the K.E of of the particles increases .
Due to increase in K.E , the particles start to vibrate with greater speed.
The energy supplied by heat overcomes the force attraction between the particles and they start moving freely . A stage comes where solid melts and is converted into liquid. And further same process continues and converts gas.
Eg: Ice ---- Water------ Gas.

EFFECT OF PRESSURE:
by applying pressure we can bring the particles of matter closer and closer . So by applying pressure gas can be converted into solid and by decreasing pressure solid can be converted into gas.
EG:
DRY ICE ----- CO2