Hafnium (Hf)
Hafnium absorbs neutrons well, so it is used in control rods for nuclear reactors.
Hafnium properties
- Atomic mass
- 178.49 u
- Category
- Transition metal
- Group
- 4
- Period
- 6
- Block
- d-block
- State at room temp.
- Solid
- Melting point
- 2,506 K (2,232.8 °C)
- Boiling point
- 4,876 K (4,602.8 °C)
- Density
- 13.31 g/cm³
- Atomic radius
- 212 pm
- Ionization energy
- 6.825 eV
- Electron affinity
- —
- Radioactive
- No, has stable isotopes
- Discovered
- 1923
Hafnium electron configuration
- Electron configuration
- [Xe] 4f14 5d2 6s2
- Full electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d2 6s2
- Electron shells
- 2 · 8 · 18 · 32 · 10 · 2
The electron configuration of Hafnium (Hf) is [Xe] 4f14 5d2 6s2. Its 72 electrons are arranged in shells as 2, 8, 18, 32, 10, 2.
Protons, neutrons and electrons in Hafnium
A neutral Hafnium atom has 72 protons and 72 electrons. Most Hafnium atoms have about 106 neutrons: the atomic mass rounded to 178, minus the atomic number 72.
Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass
How many valence electrons does Hafnium have?
2
Hafnium has 2 valence electrons, counting the electrons in its outermost s subshell. Like most transition metals, it can also use d electrons in bonding.
Hafnium orbital diagram
Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations
Molar mass of Hafnium
178.49 g/mol
One mole of Hafnium atoms (6.022 × 10²³ atoms) has a mass of 178.49 grams. Use this value to convert between grams and moles.
Hafnium facts
- Hafnium absorbs neutrons well, so it is used in control rods for nuclear reactors.
- Hafnium (Hf) has atomic number 72 and is a solid at room temperature. It was discovered in 1923.
Position in the periodic table
Hafnium is element 72, in period 6 and group 4 of the periodic table, in the d-block.
Uses of Hafnium
Hafnium oxide is used as an insulating layer in the tiny transistors of modern computer chips, allowing them to shrink while leaking less current. Hafnium is added to nickel-based superalloys for jet engine and gas turbine parts, and a niobium–hafnium alloy is used in rocket engine nozzles. Hafnium also forms the electrode tips in plasma cutting torches.
Who discovered Hafnium?
Dutch physicist Dirk Coster and Hungarian chemist George de Hevesy discovered hafnium in 1923 in Copenhagen, using X-ray spectroscopy to find it in zirconium ore. It is named after Hafnia, the Latin name for Copenhagen.
Where does the name come from?
Hafnium comes from Hafnia, the Latin name for Copenhagen, Denmark. Dirk Coster and George de Hevesy discovered the element there in 1923, at the institute led by Niels Bohr.
Same group
Compare Hafnium
FAQ
What is the electron configuration of Hafnium?
The electron configuration of Hafnium (Hf) is [Xe] 4f14 5d2 6s2. Its 72 electrons are arranged in shells as 2, 8, 18, 32, 10, 2.
How many protons, neutrons and electrons does Hafnium have?
A neutral Hafnium atom has 72 protons and 72 electrons. Most Hafnium atoms have about 106 neutrons: the atomic mass rounded to 178, minus the atomic number 72.
How many valence electrons does Hafnium have?
Hafnium has 2 valence electrons, counting the electrons in its outermost s subshell. Like most transition metals, it can also use d electrons in bonding.
What is the molar mass of Hafnium?
The molar mass of Hafnium is 178.49 g/mol. This is the same number as its atomic mass, 178.49 u.
Is Hafnium a metal?
Yes. Hafnium is a transition metal, so it is a metal.
Is Hafnium radioactive?
Ordinary Hafnium is not radioactive: it has at least one stable isotope. Like every element, it also has radioactive isotopes, most of them made in laboratories.
Where is Hafnium on the periodic table?
Hafnium is element 72, in period 6 and group 4 of the periodic table, in the d-block.