What element has the symbol 'Cm'?

The story behind the answer

Cm is the symbol for Curium. It’s an actinide element (atomic number 96) named in honor of Marie and Pierre Curie, pioneers of radioactivity. Discovered in 1944 by Seaborg and colleagues by bombarding plutonium, curium is a highly radioactive, silvery metal. Isotopes like Cm-244 have been used as alpha sources in instruments such as the Alpha Particle X‑Ray Spectrometers on Mars rovers.

Memory tip: “Cm” = “Curie + Marie” to recall Curium. Don’t mix it up with the distractors: Californium is Cf, Chromium is Cr, and Cobalt is Co.