72 Hf 178.492
Hafnium
transition metal
Properties
- Atomic number
- 72
- Atomic mass
- 178.492 u
- Category
- transition metal
- Group
- 4
- Period
- 6
- Block
- d-block
- State (room temp)
- Solid
- Outer-shell electrons
- 2
- Electronegativity
- 1.3 (Pauling)
- Density
- 13.31 g/cm³
- Melting point
- 2232.85 °C
- Boiling point
- 4602.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d²
Noble-gas shorthand: [Xe] 4f¹⁴ 5d² 6s²
Electrons per shell: 2, 8, 18, 32, 10, 2 — that's 2 in the outermost shell.
About Hafnium
Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, making it the penultimate stable element to be discovered (rhenium was identified two years later).
- Discovered by Dirk Coster
- Appearance: steel gray
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.