Question

Could you please Calculate the number of atom of 40K (potassium 40) in 1gram of KCl. Taking into account the isotopic abundance of 40K that is 0.0118%)

Answer 1

`9.53*10^(17)` atoms of 40K

Step-by-step explanation:

You can use the molecular mass and the Avogadro´s number, in the following formula:

`N_{40K=(m_(KCl))/(M_(MKCl))}*N_(Avogadro)*(IA_(40k))`

where
`m_(KCl)` is the sample mass,
`M_(KCl)` is the molecular mass of the KCl and IA(40K) is the isotopic abundance of 40K.

Now replacing the values, you can find:

`N_(40K)=(1g)/(74.5513(g)/(mol))*6.022*10^(23)mol^(-1) *0.000118`

`N_(40K)=9.53*10^(17) atoms`