A) Pt
B) Os
C) Au
D) Cu
Correct Answer: D
Solution :
Copper occurs in combined state in the following compounds Copper glance \[C{{u}_{2}}S\], Copper pyrites \[CuFe{{S}_{2}}\], Malachite \[Cu{{(OH)}_{2}}.\,CuC{{O}_{3}}\], Cuprite \[C{{u}_{2}}O\], etc. So, it does not occur in free state while Pt, Os and Au occur in free state because these are stable and unreactive. These are known as noble metals.You need to login to perform this action.
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