Practice question

**Nuclear size** order 10⁻¹⁵ m femtometer, atomic size 10⁻¹⁰ m, ratio 10⁵, nucleus contains protons and neutrons bound by strong force, density independent of A indicates incompressibility, R₀ determined from electron scattering experiments. Density = (mass/volume) , Volume = (4/3) π R³ . R³ = (1.2 × 10⁻¹⁵)³ = 1.728 × 10⁻⁴⁵ m³ . Volume = (4/3) × 3.14 × 1.728 × 10⁻⁴⁵ = 7.24 × 10⁻⁴⁵ m³ . Density = (1.67 × 10⁻²⁷/7.24 × 10⁻⁴⁵) ≈ 2.31 × 10¹⁷ kg/m³ . Using E_n = -13.6/n² eV, r_n = n² a₀, L = n h/2π, R = R₀ A^¹/³, BE = Δm c² and 1