Question

What element does Ca-37 turn into when it gives off radiation?

K-37
K-39
Sc-37
Sc-45

Answer 1

Ca-37 decays by positron emission (beta plus decay) to form K-37.

In this type of decay, a proton is converted into a neutron, giving off a positron (an antielectron) in the process. In essence, the atomic number of the element is reduced by one. The element with the atomic number of Ca minus one is potassium (K); the mass number remains unchanged (37) since it is the sum of the protons and neutrons in the nucleus, which is the same before and after decay (a proton became a neutron, and the positron isn’t a nucleon).