Atomic Structure

Q10.

(a) Give the number of nucleons and the number of electrons in an atom of Na.

(2 marks)

(b) The isotope is a positron emitter. In positron emission an up quark undergoes the following change:

u d + e⁺ + v_e

Show that charge, lepton number and baryon number are conserved in this decay.

(3 marks)

(c) Describe what happens when a positron collides with an electron.

(2 marks)
(Total 7 marks)