# Why the number of atoms of bromine in 1 mole Br₂ is not equal to Avogadro's number?

Nov 3, 2015

Because Bromine is a diatomic element.

#### Explanation:

Bromine is a diatomic element, therefore, in $1 \text{mol}$ of $B {r}_{2}$ there is Avogadro's number molecules of $B {r}_{2}$ and there is twice Avogadro's number atoms of $B r$.

Nov 3, 2015

Why not? Because the bromine molecule is made of $2$ atoms of bromine. Are we clear?

#### Explanation:

I could have Avogadro's number of any species: electrons, protons, atoms, molecules. Here I have a 1 mole of bromine molecules . Each bromine molecule consists of 2 atoms of bromine . So in my mole of molecules I have $2$ $\times$ ${N}_{A}$ of bromine atoms (${N}_{A} =$ Avogadro's number).If I have a mole of methane molecules, $C {H}_{4}$, then how many hydrogen atoms do I have?

Nov 3, 2015

Bromine is a diatomic molecule, i.e, has two atoms.

#### Explanation:

I mole or bromine refers to 6×10^23 molecules of bromine.
But 1 molecule of bromine has 2 atoms.
Hence the atom count will be exactly twice.