Metal
No plural for radium.
The chemical symbol of radium is Ra.
Radium is an alkaline earth metal, radioactive, solid, reactive.
Radium is a non metal radiop active element. Atomic mass of it is 12.
Radium react with halogens (F, Cl, Br, I), oxygen, nitrogen, water, etc. Radium is a very reactive alkaline earth metal (the Pauling electronegativity is 0,9).
Radium is a none metal element. atomic number of it is 88.
difference between knowledge classification and book classification?
classification
what is a classification of reports
does Derivative classification have the same impact and effects as original classification
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Yes. The word "classification" is singular.