Cerium

Cerium 140.116(1)   Ce 58 1s22s22p63s23p63d104s24p64d105s25p64f15d16s2 [ ? ] Lanthanide: Properties: Soft, iron-gray, malleable and ductile metal. Hazard: Ignites spontaneously in air. Moderate toxicity.

Cerium is a chemical element, having the chemical symbol Ce. Its atomic number (the number of protons) is 58. It has a standard atomic weight of 140.116 g•mol ⁻¹ and is a solid in its elemental form.

Cerium is considered to be a member of the "Lanthanide" class of elements. At a pressure of 101.325 kPa, it has a boiling point of 3,443 °C and a melting point of 778 °C.