Question: What are the 4 most expensive elements and in what years were they discovered?

Decomposition:
question: What are the 4 most expensive elements??
answer: Polonium, Actinium, Technetium, Berkelium
question: When was Polonium discovered?
answer: 1898
question: When was Actinium discovered?
answer: 1902
question: When was Technetium discovered?
answer: 1937
question: When was Berkelium discovered?
answer: 1949

Answer:
Polonium: 1898
Actinium: 1902
Technetium: 1937
Berkelium: 1949

Categories: Chemistry
History