Preservation of Water Quality

  Water pollution 1. Water pollution occurs when waste materials are thrown into water sources, making the water unsuitable for human and aquatic organisms.   2. Many humans activities either directly or indirectly pollute water...

READ MORE
Water Supply System

  1. For agricultural use, water can be used straight from its sources. For domestic and industrial use, water is treated in a water treatment plant so that it is safe and clean.   2. In our country, raw water for the water supply comes...

READ MORE
Water Purification

  Natural sources of water 1. About three-quarters of the Earth's surface is covered by water, mainly oceans.   2. The natural sources of water and its contents are shown in Table below.            ...

READ MORE
Acid and Alkali

  Acids and alkalis 1. Acids and alkalis are two important solutions.   2. Many people think that acids and alkalis are dangerous substances.   3. Actually, they are not only used in laboratories but also in many common...

READ MORE
Solution and Solubility

  1. Solution exist all around us. Oceans, rivers and even the mineral water that we drink are solutions.   2. A solution is a homogeneous (uniform) mixture that is formed when a substance is dissolved in another substance. (a) The...

READ MORE
Evaporation of Water

  1. Evaporation is the process by which a liquid changes into gas at any temperature below the liquid's boiling point.   2. For example, a mopped floor or washed hair becomes dry due to the evaporation of water.   3....

READ MORE
Next page