Define a mole. Give the significance of the mole.

One mole of any species (atoms, molecules, ions or particles) is that quantity or number having a mass equal to its atomic or molecular mass in grams.

1 mole = 6.022 x 10²³ in number (atoms, molecules, ions or particles)

1. A mole gives the number of entities present i.e, 6.022 x 10²³ particles of the substance.

2. Mass of 1 mole is expressed as M grams.