Manganese

Lore & Background

Manganese is a silvery-gray metal that resembles iron, is hard and very brittle, and oxidizes easily. It tarnishes slowly in air and rusts like iron in water containing dissolved oxygen. Naturally occurring manganese consists of one stable isotope, 55Mn, while several radioisotopes have been isolated, with 53Mn having a half-life of 3.7 million years. Manganese is part of the iron group of elements thought to be synthesized in massive stars shortly before supernova explosions.

Reader's Guide

Manganese is significant for its dual role in industry and biology. Industrially, it improves strength, workability, and wear resistance in stainless steels, and its oxides are used as oxidizing agents, rubber additives, and in glass making, fertilizers, and ceramics. Biologically, it is a critical component in dozens of proteins and enzymes, found mostly in bones, liver, kidneys, and brain, where it is bound to manganese metalloproteins like glutamine synthetase in astrocytes. Its compounds, such as potassium permanganate, serve as laboratory oxidizers and biocides in water treatment. The element also plays a key role in the oxygen-evolving complex in plants, which produces oxygen. Its isotopes, particularly 53Mn, provide evidence for nucleosynthetic processes before the Solar System's coalescence.

Did You Know?

• Manganese is essential for macronutrient metabolism, bone formation, and free radical defense systems in humans.
• The deep violet salt potassium permanganate is used as a biocide in water treatment.
• Manganese has four allotropes (α, β, γ, δ) that occur at successively higher temperatures.
• The isotope 53Mn decays to 53Cr with a half-life of 3.7 million years and is used in dating the early Solar System.