Periodic table / Transition metals

112Copernicium

Copernicium is a transition metal (predicted) in group 12, period 7. It has only ever been made a few atoms at a time, so nobody has seen it as a solid, liquid or gas.

Cn
Shells: 2, 8, 18, 32, 32, 18, 2. A simple picture: electrons do not move in circles.
Symbol
Cn
Atomic number
112 protons in the nucleus
Standard atomic weight
None. Copernicium has no stable isotopes, so the mass of a sample depends on which isotopes it holds.
Electron configuration
[Rn] 5f14 6d10 7s2 (predicted, not measured)
Electrons in each shell
2, 8, 18, 32, 32, 18, 2
Group, period, block
12, 7, d
Family
Transition metals (predicted)
State at 25 °C
not known
Electronegativity
no value
First ionisation energy
not known
Where these numbers come from

Atomic weight: IUPAC CIAAW, abridged standard atomic weights 2024. Electron configuration and ionisation energy: NIST Atomic Spectra Database. Family, state and electronegativity: PubChem. See Sources. Melting points, boiling points and densities are left out for now: published values differ between sources, and we will add them once each has been checked.