10 6C→10 5B+ 0+1e

A student claims that the equation models beta-minus decay because the atomic number of the nucleus decreases by one. In 1–2 sentences, explain the error in the student’s reasoning and what the model actually represents.

1 answer

The student is mistaken in stating that the atomic number decreases; in beta-minus decay, a neutron is transformed into a proton, which increases the atomic number by one, not decreases it. The equation actually represents beta-minus decay of carbon-10 (6C), where it decays into boron-10 (5B) and emits a beta particle (electron), resulting in an increase in the atomic number of the resulting nucleus.