What are some interesting facts about selenium?

One interesting fact about selenium is that it is named after selene, the Greek word for moon. Jons Jakob Berzellius named it after the moon because the element shared similar characteristics with tellurium, another element named after the Earth.

Though selenium is rarely found in its pure form, it is one of the most abundant elements in nature. Its impure form is widely present in metals, such as copper and lead, and is commonly extracted as a derivative of copper. Although it is toxic in high amounts and is a catalyst in many chemical reactions, trace amounts of selenium aids cellular functions. It serves as an antioxidant and provides protection against cellular damage.