Question

define radium
or
what is radium
​

Answer 1

Answer:

the chemical element of atomic number 88, a rare radioactive metal of the alkaline earth series. It was formerly used as a source of radiation for radiotherapy.

Answer 2

Answer:

Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen on exposure to air, forming a black surface layer of radium nitride.

Symbol: Ra

Discovered: 21 December 1898

Atomic number: 88

Electron configuration: [Rn] 7s2

Period: period 7