Need help explaining why transition metal complexes are coloured

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CaptainJackFail
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Explain why [CuCl4]^2- is coloured yellow.
So the mark scheme states:
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username2769500
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(Original post by CaptainJackFail)
Explain why [CuCl4]^2- is coloured yellow.
So the mark scheme states:
Name:  Capture.PNG
Views: 535
Size:  46.9 KBHow would I go about forming a sentence on the last point?
1) Compounds of transition metals do not reflect all light wavelengths and absorb some which causes "these compounds to be coloured" / "Specific colour to specific compound" and
2) The flame test colours are produced by oxidation or reduction that releases a de broglie wavelength of visible light.
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CaptainJackFail
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This is what I'm thinking;

Cucl4^2-, Cu^2+ ion contains an incompletely filled d subshell which can be then be split by the attached ligands into two different energy levels.

When white light is passed through CuCl4^2- , electrons absorb some of the energy in the light to move from lower to higher energy levels.

Eventually, the electrons will move back to a lower energy level, emitting photons of certain wavelength and frequency that corresponds to the color yellow.
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Some one
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(Original post by CaptainJackFail)
This is what I'm thinking;

Cucl4^2-, Cu^2+ ion contains an incompletely filled d subshell which can be then be split by the attached ligands into two different energy levels.

When white light is passed through CuCl4^2- , electrons absorb some of the energy in the light to move from lower to higher energy levels.

Eventually, the electrons will move back to a lower energy level, emitting photons of certain wavelength and frequency that corresponds to the color yellow.
I am sorry but that is completely incorrect. Transition metal ions do not have coloured compounds due to EMISSION of photons. Rather it is the ABSORPTION of photons that causes complementary colors to be seen
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CaptainJackFail
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(Original post by Anfanny)
1) Compounds of transition metals do not reflect all light wavelengths and absorb some which causes "these compounds to be coloured" / "Specific colour to specific compound" and
2) The flame test colours are produced by oxidation or reduction that releases a de broglie wavelength of visible light.
(Original post by Some one)
I am sorry but that is completely incorrect. Transition metal ions do not have coloured compounds due to EMISSION of photons. Rather it is the ABSORPTION of photons that causes complementary colors to be seen
Yeah, you guys are absolutely right, I did a second past paper and they rejected the word "emitted". Thanks a lot!!
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username2769500
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(Original post by CaptainJackFail)
Yeah, you guys are absolutely right, I did a second past paper and they rejected the word "emitted". Thanks a lot!!
Woohoo great!
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