Nucleon & Proton Number
- The atomic symbol of an element is used to describe the constituents of the nuclei
- An example of this notation for Lithium is:
Atomic symbol for Lithium
- When given an atomic symbol, you can figure out the number of protons, neutrons and electrons in the atom:
- Protons: The atomic number
- Electrons: Atoms are neutrals, so the number of negative electrons is equal to the number of positive protons. Therefore, this is also the atomic number
- Neutrons: Subtract the proton number from the mass number
- For the lithium atom, these numbers would be:
- Protons: 3
- Electrons: 3
- Neutrons: 7 − 3 = 4
- The term nucleon is the used to mean a particle in the nucleus – i.e. a proton or neutron
- The term nuclide is used to refer to a nucleus with a specific combination of protons and neutrons