Here's how to determine the number of protons and electrons in a ferrous ion:

1. Identify the element: Ferrous refers to the iron ion.

2. Atomic number: Iron (Fe) has an atomic number of 26. This means it has 26 protons.

3. Charge: The ferrous ion has a charge of +2 (Fe²⁺). This indicates that it has lost two electrons.

4. Number of electrons: Since a neutral iron atom has 26 electrons, the ferrous ion (Fe²⁺) has 26 - 2 = 24 electrons.

Therefore, a ferrous ion has 26 protons and 24 electrons.