# What is the difference between absorbance and absorption in the context of wavelength?

I'm writing a paper that discusses wavelength.
Which is correct: maximum absorbance or maximum absorption?

I guess both absorbance and absorption are used in the context of wavelength but which to use depends on what is meant.
Am I correct?
If correct, what is the difference between these two terms?

Thank you in advance!!

## 1 Answer

X has maximum absorbance means X has the maximum ability to absorb something, as in capacity. The amount of something actually absorbed may be less than the maximum.

X has maximum absorption means X absorbed all it can take. We may or may not know the maximum capacity, but if we know it can't absorb any more, we just found that out.

• Thank you! So now maximum absorption or absorption maximum would be the right term for what I mean, which is an actual amount. I have one more question left, the order of the two words... Google search gave similar numbers of hits (when searched in combination with "optical density"). – wanna-be-good-at-writing Nov 2 '17 at 21:58
• Maximum goes first. – LawrenceC Nov 3 '17 at 12:52