Copernicium (Cn) is a synthetic chemical element with atomic number 112. All its isotopes are highly radioactive, with the most stable isotope having a half-life of just a few seconds.

Copernicium is named after Renaissance astronomer Nicolaus Copernicus, who is best known for coming up with the heliocentric model, i.e. that it is the Earth that is orbiting around the Sun, and not the other way around.