The nucleus of a helium-4 atom contains two protons and two neutrons.
CHEMISTRY · Multi-part · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear
Problem
The nucleus of a helium-4 atom contains two protons and two neutrons.
(i) Define mass defect of a nucleus.
(ii) Given the following data, calculate the mass of the helium-4 nucleus in atomic mass units (u):
Mass of a proton =1.007276u,
Mass of a neutron =1.008665u,
Atomic mass of 4He atom =4.002603u,
Mass of an electron =0.0005486u. (Atomic mass includes the masses of two electrons.)
(iii) Using your result from part (ii), determine the mass defect Δm of the helium-4 nucleus in atomic mass units.
(iv) Hence calculate (a) the total binding energy and (b) the binding energy per nucleon of the helium-4 nucleus. Take 1u=931.5MeV/c2.