Important Elements

 

Important Elements

Carbon

Carbon is one of the most important elements. All living creatures have carbon in them and the industry uses carbon in many ways.

Carbon’s chemical symbol is C. Its atomic number is 6 and it has a mass of 12, but there are other isotopes of carbon too.

Carbon atoms like to form bonds with other atoms. They can link together with other elements and form very long chains.

A lot of carbon on Earth is found together with other elements. Carbon dioxideis in the air that we breathe out. Minerals, like limestone have carbon in them. Mixtures of carbon and hydrogen are in petroleum and natural gas.

Pure carbon does not occur very often on Earth. The best known forms of pure carbon are diamonds and graphite.

Diamonds are the hardest objects on Earth. They are in the Earth’s crust, formed under high temperatures and pressure. Diamonds are very valuable. Most of them are used in industry—to cut or polish other objects or as drilling heads in oil fields.

 Graphite is a soft grey or black mineral. Like diamonds, graphite is formed under the surface of the Earth. It is used in pencils and, because it is lightweight, you can find it in spaceships, tennis rackets and bicycles.

Chlorine

Chlorine is a poisonous greenish-yellow gas with a strong, bad smell. In nature, it can only be found together with other elements, especially in minerals. Together with sodium it forms salt (NaCl).

Chlorine is used to make water clearer and purer. In swimming pools it kills bacteria. We also use chlorine to clean metal. The industry uses chlorine compounds to produce paper, plastic, medicine and paint.

Chlorine often combines with other elements because it easily accepts free electrons from them. It has 17 protons and an atomic mass of 35.

 Aluminium

Aluminium is a very light silver metal that can be formed into any shape. It is one of the most common elements on Earth. About 8% of the Earth’s crust is made up of aluminium. But you always find it in combination with other elements, never in its pure form.

Aluminium is often used as an alloy—together with copper, magnesium or tin. When it is formed with these elements, aluminium becomes very valuable. Such alloys are very light, but strong. They do not corrode and electricity and heat can pass through them easily.

Aluminium can be as strong as steel. It is very often used to make cars and trucks as well as containers for ships. Industries make cans, pots and pans out of aluminium.

Most of our aluminium is found in rocks called bauxite. About 500 kg of aluminium can be made out of a ton of bauxite. This valuable raw material is mined in tropical and subtropical countries. Australia, Jamaica, Brazil are among the biggest producers.

 Gold

Gold is a shiny, yellow metal , probably one of the most expensive on Earth. It was one of the first metals discovered and people have been using gold for jewellery and coins for thousands of years.

Gold’s chemical symbol is Au (Latin for “aurum”) .It is a soft metal that can be pressed into many different shapes. One ounce of gold (about 30 grams) can be made into a thin wire that is 70 km long.

Gold does not rust when it gets into contact with water or air. Radios and TV sets have parts made of gold because electricity can pass through it well. Dentists use gold to make crowns, because it is easy to shape and gold crowns last a long time. Artists use thin sheets of gold to decorate objects.

Gold can be found in many rocks on Earth. In most cases , gold ore is mined deep under the surface. Sometimes gold is washed away by rain and wind. It gets into rivers where it sinks to the bottom because it is very heavy. In the middle of the 19th century a gold rush broke out all over the world. Gold was discovered in the rivers of Alaska, California and Australia.

Today, South Africa, the USA and Australia are the world’s largest gold-producing countries.