Final answer:
The Fe³+ ion in FeCl3 has lost three electrons compared to the neutral iron atom, resulting in an ion with 23 electrons.
Step-by-step explanation:
The iron ion in FeCl3, or iron(III) chloride, has three fewer electrons than the neutral iron atom. The electronic configuration of a neutral iron atom is 1s²2s²2p⁶3s²3p⁶4s²3d⁶. When forming an Fe³+ ion, it loses two 4s electrons and one 3d electron, resulting in the configuration of 1s²2s²2p⁶3s²3p⁶3d⁵. Therefore, the Fe³+ ion has 23 electrons.
In an ionic compound like FeCl3, the crystal structure reflects the formula unit, indicating that in this case, there must be three chloride ions to balance the charge of one iron(III) ion. Since Fe³+ has lost three electrons, its charge is +3, and it pairs with three chloride ions, each with a -1 charge, to form the neutral compound FeCl3. It is essential to distinguish between iron's different oxidation states since iron can form two different positively charged ions: Fe²+ and Fe³+.