Boiling and vaporization and freezing
- 1. EVAPORATION, BOILING AND FREEZING Done By Pratham Chhabhaiya
- 2. A GRAPH SHOWING STATES OF WATER 0 20 40 60 80 100 120 Ice Water Remains Constant Water Vapour Steam
- 3. EVAPORATION Evaporation takes place when a liquid is above its boiling point As 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 a liquid can be sitting in one place (maybe a puddle) and its molecules will become a gas. That's the process called evaporation. 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 a phase 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.
- 4. 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.
- 5. 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 solid– liquid transition temperatures. For example, agar displays a hysteresis in its melting and freezing temperatures. It melts at 85 °C (185 °F) and solidifies from 31 °C to 40 °C (89.6 °F to 104 °F)..
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