Boiling and vaporization

Evaporation, boiling and freezing Done By Pratham Chhabhaiya

A graph Showing States of Water

Evaporation

Evaporation takes place when a liquid is above its boiling pointAs shown in this picture a heated iron rod is inserted in water at the temperature above 100 the water has started boiling and evaporating. Sometimes aliquidcan be sitting in one place (maybe a puddle) and its molecules will become agas. That's the process calledevaporation. It can happen when liquids are cold or when they are warm. It happens more often with warmer liquids. You probably remember that when matter has a higher temperature, the molecules have a higher energy. When the energy in specific molecules reaches a certain level, they can have aphase change. Evaporation is all about the energy in individual molecules, not about the average energy of a system. The average energy can be low and the evaporation still continues.

Boiling

A liquid boils at a temperature at which its vapor pressure is equal to the pressure of the gas above it. The lower the pressure of a gas above a liquid, the lower the temperature at which the liquid will boil.

Freezing

Freezing, or solidification, is a phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point.

For most substances, the melting and freezing points are the same temperature; however, certain substances possess differing solidliquid transition temperatures. For example, agar displays a hysteresis in its melting and freezing temperatures. It melts at 85 C (185F) and solidifies from 31 C to 40 C (89.6F to104F)..

Thank you for seeing this presentation