Question

5. (b) Amongst all the elements discovered, how many are:

(ii) Non-metals

Answer 1

Element: Any pure substance which cannot be broken into two or more simpler substances by any chemical means is called an element.

• So far, chemists have discovered 118 elements. Some of the common elements are hydrogen, oxygen, nitrogen carbon, iron, copper, sodium, silver, gold, aluminium, etc.

Non-metal: An element is a non-metal, if it is a soft solid, liquid, or gas at room temperature, it has no luster and it is a bad conductor of heat and electricity.

It is non-malleable and non-ductile, and has a low melting point and boiling point. So, amongst all the elements discovered, there are 20 non-metals.