Which chemical element is named after the Moon goddess Selene?

The chemical element named after the Moon goddess Selene is selenium.

Selenium has atomic number 34 and the symbol Se. Swedish chemist Jöns Jacob Berzelius discovered it in 1817 and named it after Selene, the Greek Moon goddess. The name was chosen because selenium was found in association with tellurium, whose name comes from Tellus, the Latin word for Earth.

Selenium is a trace element required by many organisms. It forms part of selenoproteins, including enzymes involved in antioxidant defense and thyroid-hormone metabolism. The required amount is small, and excessive selenium can be toxic, so more is not automatically better.

Selenium is used in some glassmaking, electronics, pigments, and photovoltaic technologies. Its electrical conductivity changes with light, a property that helped make it useful in early photocells. The element is sometimes confused with silicon because both appear in technology, but they are different elements.