Hf
Hafnium · element 72
Transition Metal · Solid at room temperature
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).
Key facts
Atomic mass
178.492 u
how heavy one atom is
Phase (room temp.)
Solid
Density
13.31 g/cm³
how tightly packed it is
Melting point
2506 K (2233 °C)
when solid turns to liquid
Boiling point
4876 K (4603 °C)
when liquid turns to gas
Period
6
its row in the periodic table
Group
4
its column in the periodic table
Block
D-block
the neighbourhood it lives in
Electronegativity
1.3
how strongly it pulls electrons
Electron configuration
[Xe] 4f14 5d2 6s2
where its electrons live
Shells
2 · 8 · 18 · 32 · 10 · 2
electrons in each layer, inside to out
Discovered by
Dirk Coster
who found it
Appearance
steel gray
what it looks like
Source: Wikipedia