II)Cr2+ is reducing agent as its configuration changes from d4 to d3, when it is oxidized to Cr3+ .The d3 configuration have a half-filled t2g level which is very stable. On the other hand, the reduction of Mn3+ to Mn2+ results in the half-filled (d5) configuration which has extra stability hence Mn3+ acts as oxidizing agent.

Bohr's theory of the atom was proposed in the early 20th century and was based on the idea that electrons move in fixed orbits around the nucleus. According to this theory, the position and momentum of an electron in an atom can be determined with absolute precision at any given moment, which seems to contradict Heisenberg's uncertainty principle.

Heisenberg's uncertainty principle states that it is impossible to determine the exact position and momentum of a particle simultaneously. This...

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