The natural abundance of 3He is 0.000137$.
(a) How many protons, neutrons, and electrons are in an atom of 3He?
(b) Based on the sum of the masses of their subatomic particles, which is expected to be more massive, an atom of 3He or an atom of 3H (which is also called tritium)?
(c) Based on your answer to part (b), what would need to be the precision of a mass spectrometer that is able to differentiate between peaks that are due to 3He+ and 3H+?