Chemical symbol

Columns: Chemical symbol | Name | Atomic number | Origin of symbol
Pa | Protactinium | 91 | From the Greek protos and actinium . Name restricted at one time to Pa , an isotope of protactinium . This named isotope later became the official name for element 91 | Ra | Radium | 88 | From the Latin radius . Name restricted at one time to Ra , an isotope of radium . This named isotope later became the official name for element 88 | RaA | Radium A | 84 | From radium and A. Placeholder name given at one time to Po , an isotope of polonium identified in the decay chain of radium | RaB | Radium B | 82 | From radium and B. Placeholder name given at one time to Pb , an isotope of lead identified in the decay chain of radium | RaC | Radium C | 83 | From radium and C. Placeholder name given at one time to Bi , an isotope of bismuth identified in the decay chain of radium | RaC ' | Radium C ' | 84 | From radium and C ' . Placeholder name given at one time to Po , an isotope of polonium identified in the decay chain of radium

Example questions:
What is the named isotope 's chemical symbol for the element first isolated by French chemist André-Louis Debierne in 1899 ? | What is the named isotope 's chemical symbol for the element also known as heavy hydrogen ? | Which element has a named isotope symbol derived from a number with religious and spiritual significance in many cultures ? | What is the named isotope 's chemical symbol for the sixth element in group 2 of the periodic table ?

Answers:
Ac | D | Deuterium | Ra