Answer:
1) the oxidation state of the metal is +2
2) there are four d electrons
3) metal valence electrons =4 ligand valence electrons= 18
4) sp^3d^2
5) octahedral geometry
Step-by-step explanation:
[Cr(H2O)6]2+ is an octahedral complex. Octahedral complexes are known to have the metal ion in sp^3d^2 hybridization state. Since there are six ligands each bonding to the central metal ion, there are eighteen ligand valence electrons and four valence electrons from the metal present in the high spin complex.
The crystal field of high spin and low spin octahedral for a d4 ion is shown in the image attached.