Question

Find a.the total no. b)the total mass of neutrons in 7mg of 14c. (assume that mass of a neutron= 1.675 x 10-27 kg)

Answer 1

In one atom of ₆C¹⁴ , 8 neutrons present .
Find firstly number of mole of C¹⁴
$Mole = \frac {given wt.}{atomic wt} \\ mole = \frac {7mg}{14g} \\ mole = 0.5* 10^-3$
so, number of neutrons = 8 x 0.5 x 10^-3 x 6.023 x 10^23 = 24.092 x 10^23
Total mass of neutrons = 1.675 x 10^-27 x 24.092 x 10^23 kg
= 40.35 x 10^-4 kg
= 4.035 x 10^-2 kg