Atoms | website

~Electron~

~Negative charge~

~Mass: 0.000549

atomic mass unit~

~Proton~

~Positive charge~

~Mass: 1.007316 atomic mass unit~

~Neutron~

~Neutral charge!~

~Mass: 1.008701

atomic mass unit~

~Central Nucleus~

The atomic mass of an atom is made up of the number of protons and neutrons in an atom.
Because a proton and/or a neutron mass can be rounded to 1, we can just add the number of protons and neutrons instead of adding their masses.
The atomic mass does not include electrons because if its mass is rounded it has a mass of 0.

Learn more about...