👉 Cerium is a chemical element with the symbol Ce and atomic number 43. It is one of the 19 known elements in the periodic table, which are arranged from left to right, starting with hydrogen (H), proceeding clockwise by increasing number of protons. The name cerium comes from the German word for "cerium," which means "pearl" or "pear-shaped." The element is chemically similar to other elements such as iron (Fe) and nickel