원자 번호 90번의 방사성 금속 원소로, 핵연료 등으로 사용되는 악티늄족 원소.
A radioactive metallic element of the actinide series, with atomic number 90, used as a fuel in nuclear reactors.
예문:
"Thorium is considered a safer and more abundant alternative to uranium for nuclear power generation."
"The chemical symbol for thorium is Th, and it was named after the Norse god Thor."
"Scientists are researching liquid fluoride thorium reactors as a next-generation energy source."