Question

if mass of an atom is 3.32 *10^-23 gram then calculate the number of nucleons present in 2 atoms of element

Answer 1

(3.32 x 10^-23 g) / (1.6726 x 10^-24 g/nucleon) = 19.8 = 20 nucleons in one atom 
So there are 40 nucleons in two atoms.

Answer 2

The number of nucleons is 40

Explanation:

The No. of nucleons in one atom is calculated, by using the weight of 1 nucleon present in one atom.  

Given the mass of 1 atom $= 3.32 \times 10^{-23} g$

In general, the weight of one nucleon which can be either a neutron or a proton is approximately $1.67 \times 10^{-24} g$

So, the No. of nucleons in 1 atom $=\frac{\text {Weight of } 1 \text { atom }}{\text {Weight of 1 nucleon}}$

$=3.32 \times 10^{-23} \times 10^{-24}$

$=1.98 \times 10$

$\Rightarrow \text { Number of nucleons }=19.8$

$Approx \cong 20$

So, the total nucleons present in 1 atom = 20

No. of nucleons in 2 atoms $= 20 \times 2 = 40$