Hafnium (Hf), element 72 – Learn Acer periodic table

Hafnium

Transition metal, atomic number 72.

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).

Facts

Symbol Hf. Atomic mass 178.492 u. Group 4, period 6. Electron configuration [Xe] 4f14 5d2 6s2. Electrons per shell 2, 8, 18, 32, 10, 2. State at room temperature: Solid. Melting point 2232.8 °C, boiling point 4602.9 °C. Discovered by Dirk Coster.

Element data from Wikipedia, CC BY-SA 3.0.