In the complex ion [Cr(C204)2(H20)2]-, what is the oxidation number of Cr? O A. 3+
O B. 1+
O C.2+
OD. 2-
O E. 1-

A. 3+

Explanation:

In the complex, the global charge is -1.

There are 2 molecules of H₂O but water is a neutral ligand that doesn't contribute any charge to the complex

In contrast, the C₂O₄ ligand has a charge of -2. As there are 2 C₂O₄, the charge is -4.

The -4 + The charge of Cr is equal to global charge of the complex ion = -1.

Thus, Cr has a charge of +3 and right answer is:

fire could start, buildings collapsing, and ash falling from the sky.

explanation:

this is because the buildings or plants could catch on fire and the buildings would most likely collapse. lastly ash would fall because all the burning would cause ash to fall from the sky.

hope this .