This is the same type of reaction as in Problem 1. ²₁H has one proton and one neutron. It loses the neutron, to become ¹₁H, the common hydrogen nucleus that consists of one proton alone. The neutron is transferred to calcium-42 (20 protons and 22 neutrons), as you see from the Nuclear Table, making it calcium-43, ⁴³₂₀Ca.

Here the hydrogen remains hydrogen and the calcium remains calcium because the proton numbers don't change. The proton numbers determine what the chemical element is.