Proton & Nucleon Numbers
Physics: Edexcel IGCSE, topic 7.1.6
Proton and Nucleon Numbers
Proton numbers and nucleon numbers tell us information about atoms.
Proton number (Z)
- The number of protons in a nucleus tells us what element an atom is.
- For example, hydrogen atoms always have 1 proton.
Nucleon number (A)
- The nucleon number is the total number of protons and neutrons in a nucleus.
- Atoms of the same element can have different numbers of neutrons.
- For example, hydrogen can have 0, 1 or 2 neutrons.
Test yourself on Proton & Nucleon Numbers
What is the nucleon number?
Which of the following are true of proton and nucleon numbers?