What does "atomic number 42" mean?

a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel

What is a synonym for "atomic number 42"?

Common synonyms include: mo, molybdenum.

Rare ·Advanced level

Noun

1
a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel wordnet