ion colour question

[elgroucho]

If copper ions are blue and carbonate ions are colourless, why is copper carbonate green when solid?

[Gef]

A very good question. Copper ions are blue only when they have water molecules bonded to them, ie in aqueous solution or in hydrated crystals. There is no water in copper carbonate.

[Gnisy]

Well you see... er.. maybe it's... or it could be that... er.. just read the page ok? Thanks. *phew*

http://www.chemguide.co.uk/inorganic/complexions/colour. html

[NiceCupOfTea]

It's all to do with how electrons align around the metal atom, which depends on what it is bonding to.... (I did a degree in chemistry, and it's still not quite clear....)