2
$\begingroup$

We have to determine which method is true in order to find which color is absorbed and which one is transmitted?enter image description here

enter image description here

I have read in an example that $\ce{Cu^{2+}}$ absorbs red light but transmits blue.This is true if we see pyramid but not with respect to circle....How could we make jugdement in exams while solving mcq related to it?

$\endgroup$

closed as unclear what you're asking by paracetamol, Todd Minehardt, M.A.R., airhuff, ron Apr 25 '17 at 16:02

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

2
$\begingroup$

The problem with your color wheel is that it presents each color as an equal wedge. They are not. Note that red is 180 nm in width and orange is 40 nm in width. Here is a better one that I made:

a color wheel accurately representing the wavelength ranges of the colors are proportional sizes: violet from 400 nm to 440 nm; blue from 440 nm to 495 nm; green from 495 nm to 570 nm; yellow from 570 nm to 590 nm; orange from 590 nm to 620 nm; and red from 620 nm to 700 nm; and showing by way of an arrow through the center that a substance can absorb light in red wavelengths and thus transmit light in blue wavelengths

As you can see, there is a range of red wavelengths that can be absorbed to get transmittance in blue.

$\endgroup$
  • $\begingroup$ ...then what do you think about pyramidal cycle....is it correct? $\endgroup$ – M.Naeem Ahmad Apr 26 '17 at 9:44
  • $\begingroup$ It is better than the circle, but it is still flawed in that it represents each color as equal width. $\endgroup$ – Ben Norris Apr 26 '17 at 10:36

Not the answer you're looking for? Browse other questions tagged or ask your own question.