Question

How many moles of aluminum do $6.3\times {{10}^{-24}}$ aluminum atoms represent?

Answer 1

To solve this type of questions firstly we need to calculate number of moles aluminum of at present then we have to divide the given number of moles by Avogadro's number for finally find out the actual numbers of moles and mole concept The mole is unit of measurement for a amount of the substance in system unit that too not standard but International System.
A mole of the substance is the mole of particles which are defined as containing exactly by Avogadro's number $6.02\times {{10}^{23}}$

Complete answer:
Before we move forward with a solution let us discuss some important concepts of mole.
A mole is a physical quantity which represents the amount of mass of the substance required to have a collective of atoms * of the given substance.
Here mole is widely used for units that calculate the amount of the matter of substance. One mole of every substance weighs about the same as the molecular mass of the similar substance.
We use the Avogadro's numbers of * molecule per mole to calculate the number of molecules from the number of molecules represented by the Aluminum.
Now we know that a mole of aluminum atoms consist of $6.02\times {{10}^{23}}$ Aluminum atoms. So in order to get number of moles from $6.02\times {{10}^{23}}$ aluminum atoms we can calculate with;
$\dfrac{6.3\times {{10}^{-24}}atoms}{6.02\times {{10}^{23}}\dfrac{atoms}{mol}}=1.1\times {{10}^{-47}}mol$
$\Rightarrow 1.1\times {{10}^{-47}}mol$

Note: Note that the mole concept simplifies mass relation among reactant and product like we can have base and our calculation on coefficient number of molecules involved in reaction. At same time mass of substances are on a lab scale unit.