Ra vs radium

Ra and radium both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ra	Yes	No	No	No
radium	Yes	No	No	No

As nouns, Ra and radium are synonyms defined as:

Ra and radium: an intensely radioactive metallic element that occurs in minute amounts in uranium ores

Other synonyms of Ra include atomic number 88.

Ra (noun)	radium (noun)
ancient Egyptian sun god with the head of a hawk; a universal creator; he merged with the god Amen as Amen-Ra to become the king of the gods	an intensely radioactive metallic element that occurs in minute amounts in uranium ores
an intensely radioactive metallic element that occurs in minute amounts in uranium ores