What is the atomic number of manganese?
Manganese carries the atomic number 25 and exists as a hard, brittle, silvery metal. Its most common form is the stable isotope known as 55Mn.
Questions about Manganese
Short answers, pulled from the story.
When did Johan Gottlieb Gahn isolate pure manganese metal?
Swedish chemist Johan Gottlieb Gahn isolated an impure sample of pure metal in 1774 by reducing manganese dioxide with carbon. Ignatius Gottfried Kaim may have done similar work earlier but records remain uncertain.
How much manganese is required daily for children aged one to three years?
Children aged one to three need 1.2 mg daily according to U.S. guidelines. Pregnant women require 2 mg while lactating mothers need 2.6 mg.
Where are the largest known reserves of manganese located globally?
Approximately 80% of known world resources lie within South Africa. Hotazel in the Northern Cape Province holds vast identified deposits with a 2011 estimate placing these reserves at 15 billion tons.
Why does excessive exposure to manganese cause manganism?
Excessive exposure leads to manganism because manganese accumulates in basal ganglia causing abnormal movements and symptoms resembling Parkinson's disease. Breathing air with more than 5 micrograms per cubic meter causes symptoms.