Fe³⁺ ion
[Ar] 3d⁵. 5 unpaired electrons, paramagnetic.
Element or ion
Type a symbol, a name or an atomic number, add a charge such as Fe3+ or Cl-, or tap an element in the table. Orbitals fill from m = −l up, spin +½ first.
Fe3+Iron ion, 23 electrons
[Ar] 3d5
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵. Fe loses 4s² then 3d¹
Fe loses 4s² then 3d¹
- Blockd block
- Period4
- Group8
- Outer shell13
- Unpaired5
- MagneticPara
Last electron 3d
- n3shell
- l2d subshell
- m+2orbital
- s+½spin up
Step by step
- Iron has 26 electrons: [Ar] 3d⁶ 4s².
- The ion has 3 fewer, 23 electrons. Remove them from the highest n first.
- Fe loses 4s² then 3d¹.
- Fe³⁺ ion: [Ar] 3d⁵, in full 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵.
Fe³⁺ ion: the numbers
| Atomic number | 26 |
|---|---|
| Electrons | 23 |
| Period | 4 |
| Group | 8 |
| Block | d block |
| Electrons in the outer shell | 13 |
| Unpaired electrons | 5 |
| Magnetic | paramagnetic |
| Last electron | 3d: n = 3, l = 2, m = +2, s = +1/2 |
Fe³⁺ ion: quick answers
What is the electronic configuration of Fe³⁺?
Fe³⁺ has 23 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵, or [Ar] 3d⁵. Fe loses 4s² then 3d¹.
How many unpaired electrons are there in Fe³⁺?
Fe³⁺ has 5 unpaired electrons, so it is paramagnetic.
Why does Fe lose its outer electrons first?
Electrons leave from the highest n first. The 4s level fills before 3d, but once 3d holds electrons the 4s electrons are the outermost, so they are lost first.