What defines a chemical or compound colour?

Question

hi

pretty much what it says on the tin! what makes things different colours? (at an atomic level)

thanks alot

matt

Answer 1

Favourite answer

Hi Matthew

With regards to elements such as gold and copper, they have their colours due to the ability of the metal to absorb and reflect or more correctly, transmit, certain wavelengths in the visible spectrum.

In chemical compounds, its a similar phenomenon, but there are some chemical groups called 'Chromophores' which are well known for producing coloured compounds - especially organic.

Some common chromophores are C--N groups, NH3-Aromatics, C-O groups and N-N groups.

Answer 2

Different Ions Have Different Colours. Eg Copper Has A Blue Ion, And Chlorine Has A Colourless Ion. Therefore Copper(II)Chloride Has A Blue Colour.

Answer 3

It is the energy levels of the electron orbitals in its structure and bonds. It is necessary that the material has differences in energy levels such that electron quantum jumps between these levels emit or absorb light in the visible spectrum.

Colour also depends on temperature and this effect is used with thermochromic materials. As you push electrons up the energy levels with increasing temperature the corresponding wavelengths as they drop back to their ground states become shorter which is why matter has a tendency to go from red hot through to white hot with increasing temperature.

Answer 4

For transition metals and their compounds it's usually d-d transitions (for pale colours) or electron transfer reactions (for strong colours such as permanganate)

Answer 5

the bonds. electrons in bonds absorb some colors and reflect others.

Answer 6

don"t know