Calculate the number of atoms in 3mol helium
3 times Avagadro's number
= 3 * 6.022 * 10^23
= lots of them
Hey saying you have a mol of something is the same as saying you have 6*10^23 of them. It is sort of like if you say you have a dozen everyone knows you have twelve.
By the way molecules of He is the same as atoms of He because there is one atom per molecule. If it had been H2 or O2 there would have been twice as many mols of atoms as mols of molecules.
To calculate the number of atoms in a given amount of substance, you can use Avogadro's number.
Avogadro's number is defined as 6.022 x 10^23 atoms per mole. This means that in one mole of any substance, there are 6.022 x 10^23 atoms.
Given that you have 3 moles of helium, you can use this conversion factor to calculate the number of atoms:
Number of atoms = Number of moles x Avogadro's number
Number of atoms = 3 moles x 6.022 x 10^23 atoms/mole
Number of atoms = 1.8066 x 10^24 atoms
Therefore, there are approximately 1.8066 x 10^24 atoms in 3 moles of helium.