Category Chemistry

You cannot lead an active life without calcium. Be it walking, running, playing games, lifting things or even sitting straight, you cannot do any of these if not for calcium.

Every cell in our body needs calcium. Calcium helps our muscles work and send nerve impulses. It helps your body to heal cuts, scrapes and other injuries. Our bones store calcium that is necessary for our blood and cells; our bones are built and strengthened with calcium right from the day we are born.

If our diet does not include enough calcium, our body will consume the calcium that is stored in the bones. This will eventually make our bones weaker. So, it is important to have calcium rich foods like curd and milk.

Picture Credit : Google

Chalk is a white crumbly rock made of microscopic shells and is rich in calcium carbonate. Chalk is softer than limestone and is used to make a substance called putty. Putty is used to fill holes in woodwork, give a smooth finishing to the walls of buildings and seal glass into windows. Chalk is also ground into a powder called whiting, which is used in crayons, rubber paints and cosmetics.

Limestone often contains the fossils of dead animals and plants that were trapped in between the layers of sediment. Limestone is hard enough to be qualified as a building material; it is used to construct buildings, walls and paving stones. Sometimes, limestone contains phosphates. This is used to make fertilizers.

Marble is formed when chalk or limestone is buried deep underground. The pressure and heat changes the limestone or chalk into marble. It is hard, yet shiny and beautiful. Therefore, marble is used in flooring. Many sculptures and buildings around the world are made of marble. The famous Taj Mahal is built entirely of marble.

Picture Credit : Google

Calcium makes about 3.6 per cent of the Earth’s crust. But it is rarely found as a free metal. Calcium is abundant on the surface of the Earth and is mostly found as chalk, limestone, or marble.

Let us now look at how these calcium deposits are formed. The shells of living things in the ocean are made of calcium carbonate. When they die, they sink to the bottom of the ocean. Over the years, these form layers of sediments. As the layers build up, their weight squeezes the water trapped between and they stick together. Over thousands of years, the shells are transformed into sedimentary rocks called chalk, limestone and marble.

It was Sir Humphry Davy who isolated calcium for the first time in 1808.

Picture Credit : Google

To maintain good health, the human body needs a lot of minerals like iron, calcium and sodium. We have already discussed how our blood is enriched by iron. But, very few people are aware of the enormous role magnesium plays in our bodies.

After oxygen, water and food, magnesium may be the most important element needed by our bodies. In fact, it is by far the most important mineral in the body.

Magnesium is necessary for over 300 different biochemical reactions that help the functioning of the human body. Magnesium is necessary for the growth and strength of bones and teeth. It plays an important role in the synthesis of protein and is responsible for fighting infections. Magnesium is vital for muscle contraction and the functioning of nerves.

Needless to say, we need to eat a lot of food that is rich in magnesium like nuts, whole grains, dark green vegetables, seafood, and cocoa.

Picture Credit : Google

Iron and steel corrode after being exposed to oxygen or water. Corrosion is a huge trouble for ships, pipelines and oil rigs.

To prevent the troubles caused by rusting and protect the iron, another metal is used. Magnesium and zinc are often used for this purpose.

Magnesium is either attached with a cable or bolted to an object made of iron or steel. This method is known as sacrificial protection. As long as magnesium stays in contact with the steel or iron, the rust will form on the magnesium bar, since it reacts more strongly with oxygen and water than either of the other two metals. When the rust attacks the magnesium bar, it will be eaten away.

One magnesium bar must be replaced with another to protect iron or steel. Since magnesium is willingly allowed to be destroyed for the protection of iron or steel, this method is known as sacrificial protection.

Picture Credit : Google

Magnesium was not discovered until the 19th century. But much before that, humans had been using compounds of magnesium. Isolating magnesium is a tough task. This is because the compounds of magnesium are highly stable and cannot be broken down easily.

Careful studies of magnesium and its compounds began in the mid 1700’s. Some of the earliest studies on magnesium and its compounds were carried out by Joseph Black, a Scottish physician and chemist.

He conducted various experiments on compounds of magnesium and published his studies in an article. Black’s article became famous in the scientific circles and he is sometimes given credit for ‘discovering’ magnesium.

Though Black’s experiments were famous, it was Sir Humphry Davy who first isolated magnesium. Davy passed an electric current through melted magnesium oxide. The current caused the compound to break apart, forming the impure magnesium metal and oxygen gas. But this was a strenuous task, requiring a large battery with 200 pairs of metal discs to isolate the metal!