Question

Calculate the total no. Of electrons present in 7 mg c-14

Answer 1

Atomic number of nitrogen:7

Nitrogen gas=2(N) (Nitrogen gas is diatomic)

Therefore:

electrons=7

Mass=14*2= 28

We also know that total number of electrons= total number of atoms X electrons per atom

No. of molecules=6.023*10^23 *moles

No. of moles=Normal mass/molecular mass=1.4/28=0.05 moles

Therefore no. of molecules=

Therefore number of atoms=2* no. of molecules=0.6*10^23

Therefore number of electrons =7* no. of atoms=7 * 0.6 * 10^23= 4.2 *10^23 electrons.

Hope that helps