Question

Explain the mole concept. What is the importance of the mole concept?

Answer 1

The amount of a chemical substance can be expressed in different units like number of atoms, moles or grams. The chemical substance can be in very small quantities; it is not possible to calculate smaller values. Thus, the mole concept was introduced to calculate the smaller values like micrograms.

Complete answer:
Atoms are tiny particles and have very small weight. To calculate the particles that have small size, will not be able to calculate the weight in kilograms or other units. So, the mole concept was introduced.
Mole is defined as the substance containing the same number of particles as the particles in fundamental units.
It can be also defined as the particle containing exactly $6.023 \times {10^{23}}$ particles, these particles can be ions, atoms, molecules or groups.
Thus, $1$ mole is equal to $6.023 \times {10^{23}}$ particles.
There is a very great importance for the concept of mole in science.
This concept is very useful to calculate the amount of substance for micro quantities or smaller quantities.
When the amount of substance is given in the grams, it can easily be converted to the moles by knowing the molar mass of a substance and weight of substance in grams.

Note:
To convert into a number of atoms or ions, one needs Avogadro’s number. $6.023 \times {10^{23}}$ is called Avogadro's number or Avogadro’s constant. Mole is the fundamental concept and very useful in determining the amount of substance and the units of mole is mol.