Relative Mass
|
Charge
|
|
Proton
|
1
|
+1
|
Neutron
|
1
|
None
|
Electron
|
1/1836
|
-1
|
Atomic Mass & Number
Na - 23 Mass number (mass of protons + neutrons)
11 Atomic number (number
of protons)
- There are 11 protons, and neutrons + protons = 23
- Therefore there must be 23-11 = 12 neutrons.
- The relative atomic mass (Ar) is the mass of an atom compared to Carbon-12.
