Transition metals, oxidation states, really confused?

Question

OK, so one of the properties of transition metals is that they have different oxidation states, but - so do other metals, like sulphur????

Why would copper, a transition metal, have two oxides but calcium,a normal metal, form only one oxide?

Answer 1

because they're trying to make u mad...

Answer 2

First off, sulfur isn't a metal, it's a non-metal.

Secondly, transition metals can have more than one oxidation state because they can form stable ions and stable compounds in more than one oxidation state. Transition metals lose their s electrons first, so most transition metals, especially the later ones in the Table, have a stable +2 oxidation state. However, they can lose more electrons to have stable outer electron configurations depending on what they are bonded to; for example, iron is stable as the +2 ion and the +3 ion. The +3 ion is stable because it results in a d5 configuration, where each d orbital holds one electron, whereas the +2 ion is stable with certain compounds because the electrons are paired up in the d6 configuration (at this point, the d orbitals are not degenerate and there is a bigger energy separation between the d orbitals than the energy it costs to pair up electrons).

Copper has two oxidation states, +1 (which gives a d10 configuration) and +2 (d9). Even though Cu+ gives a full electron shell, which would be more stable, Cu2+ is more often seen, due to the ability of Cu to distort its bonding arrangement so that it has a lower energy configuration. In the end, energy outweighs all other considerations.

Answer 3

C: A cyanide ligand has a -1 charge. The cation in this compoud is potassium, each with a +1 charge. The anionic portion needs to be -4 overall, since the entire complex is neutral. So Ni(CN)6 has to be +4. Since each CN is a -1 charge, the Ni must be +2, a common oxidation state for a transition metal. K4 [Ni (CN)6] (+1) (+2) (-1) D: This time the nickel is a part of a cation, while the BF4 is anionic with a charge of -1. Ni(NH3)6 has to be +2 overall, as the BF4 is -1 overall and there are two of them NH3 is a neutral ligand, so the Ni is +2 once again. So: A, C, and D all have Ni in the +2 state, B has it in the +4 state Hope that helps!