One of the biggest diamonds

 The fifth biggest diamond ever discovered has been unearthed in a mine in Lesotho, a small landlocked country surrounded by South Africa. The stone has a weight of 910 carats and the size of two golf balls.

The diamond is especially valuable because it belongs to a category of gems that are colourless and do not have grave impurities.

The diamond was found in the Letseng mine, which in the past has been famous for the size and quality of gems discovered there. Diamonds that come from the Lesotho mine usually sell at a high price. Since 2006 the mine has produced some remarkable diamonds, including the Lesotho Promis, a 603-carat diamond found in 2006.

The newly found diamond will now be cut into smaller stones and polished. After that, diamond traders can actually say how much the diamond is worth, probably around $40 million.

 Gem, the British based company that operates the mine together with the Lesotho government, expects its shares to recover after prices fell and a new mine had to close in Botswana.

The largest diamond ever discovered is still the Cullinan, a 3,106-carat gem found near Pretoria in 1905. It was cut into several stones including the Great Star of Africa, the largest cut diamond in the world. The rest has been cut into the gems that are in the British Crown Jewels.

Words

• British-based = its main headquarters are in the U.K.
• discover = to find for the first time
• colourless = clear, so that you can see through it
• Crown Jewels = objects that are a symbol of the British monarchy, kept in the Tower of London
• especially = above all
• gem = beautiful stone that has been cut into a special shape
• government = people who rule a country
• grave = serious, bad
• impurity = object that is not very pure; with other substances that are mixed into it
• including = also
• landlocked = country that has no coast
• mine = deep hole in the ground that people dig in order to find coal , gold and other metals or minerals
• operate = to run a company; the owner of ...
• polish = to make something smooth, bright and shiny by rubbing it
• recover = here: to go up again
• remarkable = unusual, surprising
• share = part of a company that belongs to an individual
• surrounded = all around it
• trader = person who buys and sells things
• unearth = to dig something up from the earth
• valuable = worth a lot of money
• weight = how heavy something is
• worth = how much money you can get by selling it

 

Have scientists found the Higgs boson?

Scientists in Switzerland have made a major discovery recently. They claim they might have found a Higgs boson, or the “God particle”, as it is sometimes called. Scientists think that the Higgs boson could explain how matter gets its mass or weight. Such a particle is smaller than an atom. Scientists have been searching for this particle for almost 50 years. Without mass, particles wouldn’t hold together. In the 1960s British physicist Peter Higgs predicted that such a particle existed.

Physicists believe that the Higgs boson existed for a very short time after the Big Bang, which led to the creation of the universe about 13 billion years ago. For some time, scientists at the European Center for Nuclear Research, CERN, have been trying to create the energy that existed at that time.

CERN is the home of the Large Hadron Collider, a gigantic machine that produces high energy to smash atoms. Such a machine is used to find out how our universe developed and to look into mysteries we have not yet found an answer to. The LHC lies in a round 26 km long tunnel over a hundred meters below the Earth’s surface.  It sends particles around at light speed.

What physicists call the “standard model” describes the buildings blocks of our universe and the way it works. But there are a few missing links in this theoretical model of physics. One of them is how some particles gain their mass, while others are without mass.

The Higgs theory says that an energy field exists everywhere in the universe. As particles fly around such a field they attract Higgs bosons which are around such fields. Certain particles can attract more Higgs bosons and give them a larger mass, while others attract fewer bosons.

Some scientists are skeptical of their discovery. They say they can’t be 100% sure it is the God particle, but it is different than any other particle they have found so far.

Words

• attract = pull
• billion = a thousand million
• boson = a particle that is smaller than an atom
• certain = here: some
• claim = to say officially that something is true
• collide = crash
• creation = making of
• describe = explain
• develop = grow
• discovery = to find something new
• gain = get
• gigantic = very, very big
• light speed = the distance that light travels in a second = 300,000 km
• major = very important
• mass = weight
• missing link = piece of information that you need in order to explain something
• mystery = something that people cannot understand or explain
• particle = very small part of something
• predict = foresee
• physicist = a person who has special knowledge in physics
• recently = a short time ago
• scientist = a person who is trained in science and works in a laboratory
• skeptical = not sure, doubtful
• smash = break into pieces
• surface = the top part of something

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.