Hafnium (Hf)
[Xe] 4f¹⁴ 5d² 6s². 2 unpaired electrons, period 6, group 4, d 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.
HfHafnium, Z = 72, 178.49 u
[Xe] 4f14 5d2 6s2
In full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d² 6s²
- Blockd block
- Period6
- Group4
- Valence4
- Unpaired2
- MagneticPara
Last electron 5d
- n5shell
- l2d subshell
- m−1orbital
- s+½spin up
Step by step
- Hafnium has 72 electrons.
- Fill in (n + l) order: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d².
- Write the subshells in order of n: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d² 6s².
- Replace the xenon core with [Xe]: [Xe] 4f¹⁴ 5d² 6s².
Hafnium (Hf): the numbers
| Atomic number | 72 |
|---|---|
| Atomic mass | 178.49 u |
| Period | 6 |
| Group | 4 |
| Block | d block |
| Valence electrons | 4 |
| Unpaired electrons | 2 |
| Magnetic | paramagnetic |
| Last electron | 5d: n = 5, l = 2, m = −1, s = +1/2 |
Hafnium (Hf): quick answers
What is the electronic configuration of hafnium?
Hafnium has 72 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d² 6s², or [Xe] 4f¹⁴ 5d² 6s² in short.
How many unpaired electrons does hafnium have?
Hafnium has 2 unpaired electrons, so it is paramagnetic. 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 hafnium?
The last electron goes into 5d: n = 5, l = 2, m = −1, s = +1/2. Orbitals fill from m = −l up, spin +½ first.