Element Presentation: Manganese

How is manganese used today?

History

• In 1740, the Berlin glass technologist Johann Heinrich Pott, investigated it chemically
• Severals chemists had known of the existence of the element, but none were able to isolate it.
• The scientist who was able to isolate the element was the Swedish chemist, Johan Gottlieb Gahn.
• Modern times, it was used by glass workers to remove the pale green tint of natural glass

• Manganese is too frail, to be used as a pure metal
• The majority of manganese is found in alloys, such as steel and aluminum.
• It is generally used in very strong and stainless steels
• Steel consists of about 1% manganese, to develop strength and utility
• Manganese steel contains approx. 13% manganese. This steel is intensely strong and is used for railway tracks, safes, rifles and barrels.
• Beverage cans are made of an alloy with aluminum with 1.5% manganese to improve support to decay

Key Information

Biological Part

• Manganese is a crucial element in all known living organisms
• Many types of enzymes contain manganese
• Soils require levels of manganese
• The average adult human body contains 12mg of manganese
• We absorb approx. 4mg of manganese per day from foods such as nuts, bran, wholegrain, cereals, tea and parsley.
• Without manganese, bones become soft and fragile, causing them to break easily

• Symbol: Mn
• Atomic Number: 25
• Atomic Weight: 54. 93805
• Standard state: Solid at 25°C (77°F)
• Melting Point: 1,246°C (1518.15 K, 2273.0 °F)
• Boiling Point: 2,061 °C (2235.15 K, 3563.6 °F)
• Classification: Transition Metal
• Density: 7.43/cm3
• Appearance: Hard and brittle, silvery metal
• Group: 7
• Period: 4
• Discovery Date: 1774
• Discoverer: Johan Gottlieb Gahn
• Most common isotope: Manganese-55

Interesting Facts

• It took chemists time to discover the difference between manganese and iron, because the two metals have very similar properties and often occur together in the Earth's crust.
• Too much exposure to manganese can cause brain disorders and a psychiatric condition that causes hallucinations.
• Manganese has also been associated with Parkinson's Disease
• Although manganese is crucial to our survival, our bodies are not able to store manganese
• Manganese dioxide was used as paint thousands of years ago

Sources

http://www.rsc.org/periodic-table/element/25/manganese

http://www.ducksters.com/science/chemistry/manganese.php

http://www.chemistryexplained.com/elements/L-P/Manganese.html

Where is manganese found on earth?

• Manganese is found in the Earth's crust
• It is the fifth most sufficient metal
• Found in many minerals which are extensively distributed, with pyrolusite (manganese dioxide) and rhodochrosite (manganese carbonate)
• Mining areas include China, Africa, Australia and Gabon.
• Also can be found in ocean water and atmosphere
• A decent amount of manganese is expected to exist on the ocean floor
• These amounts contain about 24% manganese, along with reduced amounts of other elements

Manganese Presentation

By Meena L.