What is chalk? Detailed answer

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What is chalk? Detailed answer

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What is chalk?

There is no person in the whole world who has not encountered chalk in his life. In millions of classrooms on Earth, students write with chalk on the blackboard. What would a teacher do without chalk?

Do you know that in the beginning chalk was an animal? In the waters of the oceans there are various types of tiny plants and animals. One of them is a single-celled creature called "foraminifera" with a lime shell.

As they die, they sink to the ocean floor. Over time, a thick layer of these shells forms. Of course, this takes millions of years. Gradually, this layer cements and turns into soft limestone, which we call chalk.

As we already know, various changes on the Earth turned the seabed into land. This happened in the English Channel. The layers of chalk, which were on the seabed, were raised above the surface of the sea. The most loose areas were washed away by water, leaving high chalk cliffs. The best known are at Dover on the English side and at Dieppe on the French side.

In various parts of the world, chalk lies far from the sea, where the sea once was. An example of this is the states of Kansas, Arkansas and Texas in the USA. But the best natural chalk is obtained in England.

For hundreds of years, people have been using chalk for various purposes. The chalk we use in class is mixed with binders to keep it from crumbling. The best school chalk is 95% chalk. By adding various dyes, you can get chalk of any color.

After pulverizing, washing and filtering, the chalk produces a white powder, which is used to add to putty, paint, drugs, paper, toothpaste and various powders!

Author: Likum A.

Random interesting fact from the Great Encyclopedia:

What is the fold of skin between the nose and upper lip called?

The fold of skin between the nose and the upper lip is called the philtrum or, in Latin, the filtrum. It is in this place that the parts of the human face are connected during the development of the embryo in the second or third month of pregnancy.

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