Transcript Transition Metal Manganese

Transition Metal
Manganese
5E Ho Sin Yin(9)
5E Tong Ka Wai(19)
5E Tso Ka Wing (20)
What is Manganese?
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Transition metal
Atomic number: 25
No. of protons: 25
No. of neutrons: 30
Relative atomic mass: 54.94
State: solid
Electronic diagram
• Layers of electron shells: 4 (Period4)
Characteristics
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Color: silver-gray
Chemically active
Hard, very brittle
Hard to melt, but easily oxidized
Reactive when pure
Powder: Burn in oxygen
Reacts with water (rusts like iron)
Dissolves in dilute acids
Oxidation state
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+2: most stable, pale pink color (aq)
+4: brown/black color, found in MgO2
+7: purple color, found in MnO4+6: green color
Manganese ore
Manganese oxide
Applications
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Iron and steel production
Key component of low-cost stainless steel
Key component of certain aluminum alloys
Decolorize glass
make violet colored glass
• Manganese dioxide: catalyst (催化劑)
• Manganese oxide and manganese carbonate:
fertilizers and ceramics (製陶業), making
manganese compounds materials
Importance
• Used extensively to produce a variety of
important alloys. E.g. soft drinks cans (improve
stiffness (堅硬度) and corrosion resistance)
• Human body: Manganese-containing enzymes to
metabolize carbohydrates, cholesterol, and
amino acids. (氨基酸)
• Human contains 10 - 20 mg manganese. (1/4 in
bone, the rest evenly distributed through our
tissues)
Humans lack of Manganese?
Health Effects:
• Fatness
• Blood clotting (血凝結)
• Skin problems
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Skeleton disorders (骨骼疾病)
Birth defects (缺陷)
Changes of hair color
Neurological symptoms (精神病)
~The End~