Manganese is element number 25, a metal with the symbol Mn. At first it was called “manganesium,” and its name comes from the same place as magnesium’s.
Atomic number 2554.94
MnManganeseマンガン (mangan)
Symbol
Mn
Atomic weight
54.94
Place in the table
Period 4 · Group 7
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
Easy to mix up with magnesium
The symbol Mn comes from a Greek word named after a place, the same place that gave magnesium (Mg) its name. Manganese was discovered in 1774 and was first called “manganesium.”
Manganese in the body
An adult body contains 10–20 mg of manganese. About 25% is in the bones, and the rest is spread fairly evenly through the body.
Manganese is in the fourth row of Group 7. Next door, in Group 8, is iron.
Think about it
Q1What problems can confusing names cause?
Q2How does 10–20 mg compare with a one-yen coin (1 g)?
Q3Besides their names, are manganese and magnesium alike in any way?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Compare the amounts in an adult body: iron 3–4 g, zinc about 2,000 mg, copper about 100 mg, manganese 10–20 mg. Metals from the same row can differ a lot.