. What is mole and how it is related with avogadros number?
One mole is an amount of substance containing Avogadro's number of particles. Avogadro's number is equal to 602,214,199,000,000,000,000,000 or more simply, 6.02214199 × 1023.
A mole (symbol mol) is defined as the amount of substance that contains as many atoms, molecules, ions, electrons or any other elementary entities as there are carbon atoms in exactly 12 gm of 12C. The number of atoms in 12 gm of 12C is called Avogadro’s number (NA).
NA = 6.022 × 1023
From mass spectrometer we found that there are 6.022 x 1023 atoms present in 12 gm of C – 12 isotope. The number of entities in 1 mol is so important that it is given a separate name and symbol known as Avogadro constant denoted by NA. i.e. on the whole we can say that 1 mole is the collection of 6.022 x 1023 entities. Here entities may represent atoms, ions, molecules or even pens, chairs , paper etc also include in this but as this number (NA) is very large therefore it is used only for very small things.
How big is a Mole? One mole of marbles would cover the entire Earth (oceans included) for a depth of three miles. One mole of $100 bills stacked one on top of another would reach from the Sun to Pluto and back 7.5 million times. It would take light 9500 years to travel from the bottom to the top of a stack of 1 mole of $1 bills.