What are Elements?

 

Chemical Symbols

We have seen that there are more than 100 different elements (including those that have been made in laboratories). Chemists use a shorthand way of referring to them. They have given each element a symbol.

Sometimes the symbol is the first letter of the English name of the element. For example, the symbol for oxygen is O.

Sometimes the symbol is the first letter of the English name of the element plus another letter from its name. For example, the symbol for helium is He.

Sometimes the symbol is taken from the name of the element in another language. For example, the symbol for sodium is Na, from the old Latin name ‘natrium’.

The first letter of the symbol is always upper case. The second letter, if there is one, is always lower case.

Elements on Earth

Some elements, such as copper and gold, have been known for thousands of years. Others, such as radium and aluminium, have only been discovered more recently.

Image Source:https://media.cheggcdn.com/study/b64/b645863e-34a7-45e5-ba24-3624e0090a9d/13188-2-48IR1.png

Some elements are very abundant (common) on Earth, and some are rare. The pie chart shows the approximate proportions of the various elements that are found in the Earth’s crust.

Is water an element?

People believed that water was an element until about 1800. It was only then that a scientist passed electricity through water and found that it split up into two gases – hydrogen and oxygen.

Electricity can be used to split water into the elements hydrogen and oxygen.