the process of particles @ the SURFACE of a liquid changing from a liq. 2 a gas when the liq. is BELOW boiling

Question

im thinking evaporation but not sure...

Answer 1

evaporation is correct

Answer 2

Yes, it is evaporation and can occur at all temperatures below the boiling point. Boiling is accelerated evaporation. Evaporation occurs because some of the molecules in the liquid have velocities and thus kinetic energies higher than the surface tension, which is the attractive force among the molecules and thus keeps the surface intact. Thus, the higher energy molecules leave the liquid surface and go into the space above the liquid as vapor. When the space is above is filled with sufficient vapor, some of the intermolecular collisions lead to the molecules being kicked back into the liquid. Thus the surface of the liquid is anything but static. It is a dynamic entity.

If the vessel is open, the vapor molecules keep expanding farther and farther. That is why any smelly substance soon spreads all over the room. If the vessel is closed, a dynamic equilibrium is soon established between the liquid and the vapor phase. The vapor pressure is called Saturated Vapor Pressure and is expressed in mm of mercury. Each liquid has a definite SVP at a given temperature.

I hope the above helped. If needed, ask for more.

Answer 3

Absolutely right. Boiling involves bubbles appearing from throughout the liquid, but evaporation (below the boiling point) happens only at the surface.

Answer 4

Evaporation is correct.

Sublimation when this happens at the surface of a solid with no intermediate liquid form.