What does MC stand for?

Moscovium

Moscovium, with the symbol Mc and atomic number 115, is a synthetic chemical element that was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. It is an extremely radioactive element, with its most stable known isotope, moscovium-290, having a half-life of about 0.8 seconds. Moscovium is a member of the p-block transactinide elements and is the heaviest element in group 15 of the periodic table, although a sufficiently stable isotope is not known at this time to allow chemical experiments to confirm its position as a heavier homologue to bismuth.

The discovery of moscovium was a significant milestone in the field of nuclear chemistry, expanding our understanding of the limits of the periodic table and the stability of superheavy elements. Research into moscovium and its compounds is purely theoretical at this stage, due to its short half-life and the difficulty in producing sufficient quantities. However, scientists predict that if enough moscovium could be produced, it would exhibit properties similar to those of bismuth, such as forming a +3 oxidation state, but with possibly more pronounced relativistic effects due to its high atomic number.