is it toxic to humans?
Yes, exposure or intake may led to manganism, neurodegenerative disorder,  Parkinson's disease.
Manganese
Excessive exposure or intake may lead to a condition known as manganism, a neurodegenerative disorder that causes dopaminergic neuronal death and symptoms similar to Parkinson's disease.
what is the oxidation number of manganese in the mn ion It is oxidation state +7. is it a metal? Yes, it is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. where are these widely found? It is not found as a free element in nature; it is often found in minerals in combination with iron. what are some of its uses? Steel production, additive in unleaded gasoline, dry cell battery..
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Manganese [SEP] Toxicity
Excessive exposure or intake may lead to a condition known as manganism, a neurodegenerative disorder that causes dopaminergic neuronal death and symptoms similar to Parkinson's disease.