Fossil Fuels
Coal Coal supplies us with about 28% of all the energy used. It is burned to make water hot and produce steam. The steam, in turn,generates electric power or operates steam engines. In many countries people use coal to heat their homes. Coal mining has caused many problems in the past. Accidents in coal mines kill workers every year and breathing coal dust can lead to lung diseases. Although many factories have installed cleaning filters, coal emits sulphur oxides that pollute our air […]
World of Energy
Energy is another word for power. It makes things move and machines work. Itprovides us with light and we use it to heat and cool our houses and offices, to cook our food, and to transport people and goods. Sources of energy Almost all energy on earth today comes directly or indirectly from the sun. Over millions of years the […]
The Nile River
The Nile River is the longest river in the world. It flows northward from the lakes of Central Africa to the Mediterranean Sea. However, the Nile carries less waterthan many other rivers because it flows through the Sahara desert in the north. 97% of Egypt’s population lives in the river’s valley. Africa’s biggest river drains about 10 percent of the continent. It flows through many countries of eastern and […]
Tsunamis – Killer Waves
On December 26, 2004 a great underwater earthquake near the coast of Indonesia caused the greatest tsunami in history. 280,000 people died and many coastal villages were wiped out. The word tsunami comes from the Japanese : tsu means harbour and nami waves. A tsunami is a series of ocean waves that can travel over hundreds of kilometres at a very high speed. They are hardly seen in the […]