Krypton (Kr)
[Ar] 3d¹⁰ 4s² 4p⁶. 0 unpaired electrons, period 4, group 18, p block.
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.
KrKrypton, Z = 36, 83.798 u
[Ar] 3d10 4s2 4p6
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶
- Blockp block
- Period4
- Group18
- Valence8
- Unpaired0
- MagneticDia
Last electron 4p
- n4shell
- l1p subshell
- m+1orbital
- s−½spin down
Step by step
- Krypton has 36 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶.
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶.
- Replace the argon core with [Ar]: [Ar] 3d¹⁰ 4s² 4p⁶.
Krypton (Kr): the numbers
| Atomic number | 36 |
|---|---|
| Atomic mass | 83.798 u |
| Period | 4 |
| Group | 18 |
| Block | p block |
| Valence electrons | 8 |
| Unpaired electrons | 0 |
| Magnetic | diamagnetic |
| Last electron | 4p: n = 4, l = 1, m = +1, s = −1/2 |
Krypton (Kr): quick answers
What is the electronic configuration of krypton?
Krypton has 36 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶, or [Ar] 3d¹⁰ 4s² 4p⁶ in short.
How many unpaired electrons does krypton have?
Krypton has 0 unpaired electrons, so it is diamagnetic. Put one electron in each box of a subshell before pairing (Hund’s rule) to see them.
What are the quantum numbers of the last electron of krypton?
The last electron goes into 4p: n = 4, l = 1, m = +1, s = −1/2. Orbitals fill from m = −l up, spin +½ first.