Definitions
There is 1 meaning of the phrase
Atomic Number 21.
Atomic Number 21 - as a noun
A white trivalent metallic element; sometimes classified in the rare earth group; occurs in the scandinavian mineral thortveitite
Synonyms (Exact Relations)
scscandium13Example Sentences
"The atomic number 21 corresponds to the element scandium in the periodic table."
"Scandium's atomic number 21 indicates the number of protons in its nucleus."
"At room temperature and pressure, the atomic number 21 element is a silvery-white metal."
"The position of scandium with atomic number 21 in the periodic table is between calcium and titanium."
"Isotopes of the atomic number 21 element have different numbers of neutrons."
