We need these additional facts before looking at helum some more.
|
1. The mass of an electron is very small compared to a proton.
|
|
2. The nucleus of an atom may also contain one or more neutrons.
|
|
3. The mass of a neutron is about the same as the mass of a proton.
|
|
4. A neutron has no charge. |



(c) Copyright 1999. All rights reserved.