Highest oxidation state of Mn is exhibited in $$Mn_2O_7$$. The correct statements about $$Mn_2O_7$$ are
(A) Mn is tetrahedrally surrounded by oxygen atoms
(B) Mn is octahedrally surrounded by oxygen atoms
(C) Contains Mn - O - Mn bridge
(D) Contains Mn - Mn bond.
Choose the correct answer from the options given below

$$Mn_2O_7$$ (dimanganese heptoxide) is the anhydride of permanganic acid ($$HMnO_4$$). In this compound, manganese is in its highest oxidation state of +7.

Structure of $$Mn_2O_7$$:

(A) Mn is tetrahedrally surrounded by oxygen atoms:

True. Each Mn atom is surrounded by four oxygen atoms in a tetrahedral arrangement — three terminal oxygen atoms and one bridging oxygen atom.

(B) Mn is octahedrally surrounded by oxygen atoms:

False. The coordination is tetrahedral, not octahedral.

(C) Contains Mn-O-Mn bridge:

True. The two $$MnO_4$$ tetrahedra are connected through a common oxygen atom, forming a Mn-O-Mn bridge. The structure consists of two $$MnO_3$$ units joined by a bridging oxygen: $$O_3Mn-O-MnO_3$$.

(D) Contains Mn-Mn bond:

False. The two manganese atoms are connected through a bridging oxygen, not by a direct Mn-Mn bond.

The correct statements are A and C only.

The answer is Option A: A and C only.