For oxygen, which has an atomic number of 8, the number of protons is always equal to the atomic number. Therefore, each oxygen atom will have 8 protons.
Oxygen isotope with a mass number of 16:
- Number of protons: 8 (atomic number)
- Number of neutrons: Mass number - Number of protons = 16 - 8 = 8 neutrons
- Number of electrons: Number of protons (in a neutral atom) = 8 electrons
Oxygen isotope with a mass number of 18:
- Number of protons: 8 (atomic number)
- Number of neutrons: Mass number - Number of protons = 18 - 8 = 10 neutrons
- Number of electrons: Number of protons (in a neutral atom) = 8 electrons
To summarize:
For Oxygen-16:
- Protons: 8
- Neutrons: 8
- Electrons: 8
For Oxygen-18:
- Protons: 8
- Neutrons: 10
- Electrons: 8