Quizzes
Topic Content:
- Condensation & Freezing
- Sublimation
- Osmosis
- Diffusion
Other phenomena that can be explained using kinetic theory include;
4. Condensation & Freezing:
Condensation is when gas/vapour loses some of its kinetic energyEnergy is the ability to do work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, and electrical energy. Units of Energy: The SI unit... More and changes into a liquid, for example, steam to water.
Freezing is a change of state where a liquid turns into a solid when its temperature is lowered, and it loses heat energy, below its freezing point. The freezing point of a liquid is the same as its melting pointThe temperature at which a solid changes its state to liquid at atmospheric pressure is called the melting point of that liquid. The melting point is usually defined as the point... More.
5. Sublimation:
This is when solid changes directly into a gas, without passing through the liquid state, for example, iodine crystals to iodine vapour.
An increase in temperature causes the kinetic energy of particles to increase. This allows the particles to overcome the intermolecular forces and become mobile. Low pressure also increases the particles’ kinetic energy. Sublimation occurs as the particles escape the solid and disperse as a gas.
6. Osmosis:
Osmosis is the movement of molecules of water or gases, from a region of a higher concentration to a region of lower concentration, through a semi-permeable or differential membrane. The molecules move from where there are many to where there are few because they gain kinetic energy.
7. Diffusion:
Diffusion refers to the process of particles, water or gases, moving from an area of high concentration to one of low concentration, that is, from a crowded region to a less crowded region.
Gaseous particles are in constant random motion. Gaseous particles tend to undergo diffusion because they have kinetic energy. Diffusion is faster at higher temperatures because the gas molecules have greater kinetic energy.
Evaluation Questions:
1. State three assumptions of kinetic theory.
2. Outline the kinetic theory of matter.
3. State 4 factors that affect evaporation.
Reading Assignment: Spectrum basic science for junior secondary schools, book 2, pages 124 – 128.