# Which particle, when emitted from the nucleus of an atom, would have the greatest effect on the mass of the atom?

Jul 3, 2017

Consider the following.

#### Explanation:

The nucleus contains only protons and neutrons, so we would have to compare the mass of both of them.

Proton: $\approx 1.01 a \mu$ or $1.6726 \cdot {10}^{-} 27 k g$
Electron: $0.00055 a \mu$ or $9.1 \cdot {10}^{-} 31 k g$

As you can tell, a proton has much more mass than an electron, so it should have the greater effect on the mass of the atom.

However, emitting a proton does change the element of the atom, so I am not certain of which one actually affects the mass the greatest. It may possibly depend on the element of the atom itself!