Manganese

Manganese 54.938049(9)   Mn 25 1s22s22p63s23p63d54s2 [ ? ] Transition metal: Properties: Grayish-white. hard, brittle metal. Hazard: Manganese dusts and fumes are toxic.

Manganese is a chemical element, having the chemical symbol Mn. Its atomic number (the number of protons) is 25. It has a standard atomic weight of 54.938049 g•mol ⁻¹ and is a solid in its elemental form.

Manganese is considered to be a member of the "Transition metal" class of element. At a pressure of 101.325 kPa, it has a boiling point of 2,061 °C, and a melting point of 1,246 °C.