C. 3. Translate the text What Is Fire? and then discuss it with your partner

Date: 2015-10-07; view: 520.

Fire is the result of a chemical reaction in which heat and light are produced. Rapid oxidation, combined with some fuel, causes fire. This chemical process is known as combustion. The necessary oxidizer in fires is usually oxygen. Only when oxygen functions as an oxidizer is the process referred to as "fire." For there to be a fire, three elements must be present: oxygen, fuel, and heat.

In order to extinguish a fire, one of the three necessary elements must be removed. For example, if something is burning and the source of oxygen is removed by smothering the flame, the fire is extinguished. Most of us have put a small burning candle in a glass jar and placed a cover over the top. The flame goes out when the supply of oxygen is cut off.

Because heat is necessary to the production of fire, removal of heat can be used to cool the blaze to a point below the ignition tem­perature. The temperature at which a substance begins to burn (ignites) will vary. The ignition temperature of a solid material is higher than is that of a liquid, for example. The best means of reducing the temper­ature of many fires is to apply water. Water will absorb the heat and in the process extinguish the fire.