K⁺ ion
[Ar], the same as argon. 0 unpaired electrons, diamagnetic.
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.
K+Potassium ion, 18 electrons
[Ar]
In full: 1s² 2s² 2p⁶ 3s² 3p⁶. K loses 4s¹. Same electrons as argon (Ar).
K loses 4s¹like Ar
- Blocks block
- Period4
- Group1
- Outer shell8
- Unpaired0
- MagneticDia
Last electron 3p
- n3shell
- l1p subshell
- m+1orbital
- s−½spin down
Step by step
- Potassium has 19 electrons: [Ar] 4s¹.
- The ion has 1 fewer, 18 electrons. Remove them from the highest n first.
- K loses 4s¹.
- K⁺ ion: [Ar], in full 1s² 2s² 2p⁶ 3s² 3p⁶.
K⁺ ion: the numbers
| Atomic number | 19 |
|---|---|
| Electrons | 18 |
| Period | 4 |
| Group | 1 |
| Block | s block |
| Electrons in the outer shell | 8 |
| Unpaired electrons | 0 |
| Magnetic | diamagnetic |
| Last electron | 3p: n = 3, l = 1, m = +1, s = −1/2 |
K⁺ ion: quick answers
What is the electronic configuration of K⁺?
K⁺ has 18 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶, or [Ar], the same as argon. K loses 4s¹.
How many unpaired electrons are there in K⁺?
K⁺ has 0 unpaired electrons, so it is diamagnetic.
Why does K lose its outer electrons first?
The electrons in the outermost shell are held least strongly, so they are removed first, leaving [Ar].