Particulate Nature of Matter

All important points and deifinitions

Melting Point

Min. Temp. at which a solid melts into a liquid at atmospheric pressure.

Why does the solid turn into a liquid when heated?

When Vibrations become strong enough to overcome the interparticle forces, the solid begins to melt into a liquid.

Features of Fluid

Flow, No fixed shape retained.

Why solid has definite shape and volume?

Because their constituent particles are tightly packed.

Why do gases compress

The amount of space between particles of gases is significantly more then that of solids. This difference of interparticle spacing allows us to compress gases but not solids or liquids.

What happens on heating

Particles gain energy and vibrate more vigorously.

Boiling Point

The temperature at which a liquid boils and turns into vapour at atmospheric pressure, forming bubbles inside the liquid.

Evaporation

Slow process of vapour formation that occurs at all temperatures, but only from the surface of the liquid