72
Hf
Hafnium
Transition metal period 6 group 4 d-block discovered: 1923
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 72
- Atomic mass
- 178.49 a.m.u.
- Electron configuration
- [Xe]6s2 4f14 5d2
- Electronegativity
- 1.3 on the Pauling scale
- Atomic radius
- 212 pm
- Ionization energy
- 6.825 eV
- Oxidation states
- +4
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 2506 K (2 232,85 °C)
- Boiling point
- 4876 K (4 602,85 °C)
- Density
- 13.3 g/cm³