What always changes during transmutation of an atom?

Question

What always changes during transmutation of an atom?

a) the number of electrons

b) the number of energy levels

c) the number of protons and neutrons

d) the mass number

Answer 1

c) the number of protons and neutrons

Technically, transmutation only involves a change in the number of protons, but this is usually accompanied by a change in neutrons, as well.

a) could also be considered a correct answer, since the number of electrons will change to balance the change in the number of protons for the neutral atom.

Answer 2

c) the number of protons and neutrons...

Transmutation is the change of an element into another element. Spontaneous radioactive decay of an alpha particle (2 protons, 2 neutrons or Helium) is an example...