Hafnium (Hf): electron configuration, atomic mass and facts
Hafnium (Hf) is element 72 of the periodic table, a transition metal in period 6, group 4. Its electron configuration is [Xe] 4f14 5d2 6s2, with electrons arranged in shells 2, 8, 18, 32, 10, 2, and its standard atomic weight is 178.49 u.
▶ Watch Hafnium’s electrons orbit in the interactive periodic tableHafnium at a glance
| Symbol | Hf |
|---|---|
| Atomic number | 72 |
| Atomic mass | 178.49 u |
| Category | Transition metal |
| Group | 4 |
| Period | 6 |
| Block | d-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d2 6s2 |
| Noble-gas shorthand | [Xe] 4f14 5d2 6s2 |
| Electrons per shell | 2, 8, 18, 32, 10, 2 |
| Electronegativity (Pauling) | 1.3 |
| State at 20 °C | solid |
Where is Hafnium on the periodic table?
Hafnium is in period 6, group 4, in the d-block. The period number matches its 6 electron shells, and the block names the subshell its last electrons fill. In the same group, Zirconium sits directly above it and Rutherfordium sits directly below it. Elements in the same column of the d-block often have similar chemistry.
How to work out the electron configuration of Hafnium
Put 72 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁶ (18), 4s² (20), 3d¹⁰ (30), 4p⁶ (36), 5s² (38), 4d¹⁰ (48), 5p⁶ (54), 6s² (56), 4f¹⁴ (70), 5d² (72). In shorthand, [Xe] stands for the 54 electrons of xenon, giving [Xe] 4f¹⁴ 5d² 6s².
How electronegative is Hafnium?
Hafnium has a Pauling electronegativity of 1.3, ranking 62 of the 100 elements with a known value (fluorine is highest at 3.98). That is low: it tends to give up electrons and form positive ions.
Frequently asked questions
What is the electron configuration of Hafnium?
The electron configuration of Hafnium (Hf) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d2 6s2. In noble-gas shorthand it is written [Xe] 4f14 5d2 6s2.
How many electrons does Hafnium have in each shell?
Hafnium has 72 electrons arranged in shells as 2, 8, 18, 32, 10, 2.
What is the atomic mass of Hafnium?
The standard atomic weight of Hafnium is 178.49 u, so one mole of Hafnium atoms has a mass of about 178.49 g.
Is Hafnium a metal?
Yes. Hafnium is a transition metal.
Explore nearby elements
More transition metals: Tantalum, Tungsten, Rhenium, Osmium, Iridium, Platinum. See all elements on the periodic table.