Question

Order of magnitude of density of Uranium nucleus :

(1)10^20 kg/m^3
(2)10^17 kg/m^3
(3)10^14 kg/m^3
(4)10^11 kg /m^3

Answer 1

M ≈ A x (1.67 x 10⁻²⁷)
where A is the mass number

V = 4/3 λr³
= 4/3 x 22/7 x [(1.3 x 10⁻¹⁵)A¹/₃]³
= 8.2 x 10⁻⁴⁵ x Am³

density = m/V
= 1.67 x 10⁻²⁷x A/ 8.2 x 10⁻⁴⁵ x A
= 2.0 x 10¹⁷ kg/m³

so the ans is option 2