Rubidium (Rb), with an atomic number of 37, has 37 protons.
For a neutral atom of rubidium, the number of electrons is also 37 (equal to the number of protons). However, since the ion has a 1+ charge, it has lost one electron. Therefore, the number of electrons in the Rb^+ ion is:
- Electrons = 37 - 1 = 36
The mass number of 85 indicates the total number of protons and neutrons. To find the number of neutrons, you can subtract the number of protons from the mass number:
- Neutrons = Mass number - Protons = 85 - 37 = 48
So for the rubidium ion with a 1+ charge, we have:
- Protons: 37
- Neutrons: 48
- Electrons: 36