It was based upon spectrometry. So if you have a transmittance of 10 EU and an Absorbance of 2.0, what is Io (I initial) and T %? Use the formulas: A=log(1/T), T=(I/Io), %T= (I/Io)x100, A=log(Io/I) I did this then got stuck, but I answered T%= 1% How do I post a picture larger? https://picasaweb.google.com/lh/photo/Gga7k3pdoUq9JNyoAERRodMTjNZETYmyPJy0liipFm0?feat=directlink

Isn't I( initial ) just set to 100? No matter what it is (I) would be a percentage of that if I'm looking at this right. Good luck!

Sounds logical, I wish our teacher told us that. Brainfuse didn't even know how to do this problem I already took my final, but I was stuck on this question.

MHT, I think you are right, something is wrong with the question. Transmittance should be unitless, either as a ratio <1, or as a percentage, not EU (is that Euros?). Absorbance is in units of AU (absorbance units). And, why ask what Io is, when it is always defined as 100%? Doesn't make sense...

I hope the teacher didn't screw us over for the final, but EU is energy units so its not really a unit of measurement.

I’m very sorry, but IMO your answer is not exactly right. By definition , see please http://en.wikipedia.org/wiki/Transmittance ,transmittance is T=Iout/Iin (1) where Iin is the intensity of the incident radiation and Iout is the intensity of radiation coming out of the sample. The absorbance is A=Log(Iin/Iout) (2) We know that Iout = 10 EU and A = 2. From (2) we have Iin / Iout = 10** A = 10**2=100. Thus T = 1/100 =1% From (1) Iin = Iout*100 = 1000 EU

Thanks for the help but one thing that puzzled me is that If A= log(1/T) and T=10 it comes out to be -1. Do we ignore the T=10?

According to definition T=Iout/Iin. Thus, T is always less or equal to 1 (0<T<1). In your case: T=0.01=1%, Iout=10 EU, and Iin =1000 EU. If T=1/100 than 1/T=100 and A=log(1/T)=log(100)=2. EU is complicated energy unit.

If (0<T<1) than (∞>1/T>1) A=log(1/T) If 1/T=1 than A= log(1)=0 If 1/T=∞ than A=log(∞)=∞ So, (0<A<∞) and Amax=∞