Replacing a column in a table with values dependent on the current values in the column?

I currently have a table of absorbances vs. wavenumbers. How would I change that to a table of %transmittances vs. wavenumbers? The relationship is given by

%Transmittance = (10^(-absorbance))*100]

I've tried:

newtable = Replace[currenttable, i -> ((10^(-i))*100)]

No errors occur, but nothing happens.

• You may use newtable = currenttable; newtable[[All, i]] = (10^(-newtable[[All, i]]))*100; where i is the number of the column. If you wonder what [[ ]] is, look up Part in the documentation. – Henrik Schumacher Apr 9 at 5:53
• Is the table structured as a list of pairs in form {wave-number, absorbance}? – m_goldberg Apr 9 at 5:54
• If you could show a brief excerpt of your table in your question, it would be easier to help you more effectively. – MarcoB Apr 9 at 5:59

Contrived data based on the element form {wave-number, absorbance}.

SeedRandom;
With[{n = 5}, data = Sort @ Transpose[{RandomInteger[100, n], RandomReal[1., n]}]]
{{4, 0.142803}, {6, 0.628702}, {15, 0.290081}, {54, 0.0292846}, {66, 0.105067}}

Assuming you want to keep the original data and not destructively change the 2nd column in it, you could proceed as follows:

newdata = data;
newdata[[All, 2]] = 100 10^-data[[All, 2]];
newdata
{{4, 71.9776}, {6, 23.5124}, {15, 51.2765}, {54, 93.4793}, {66, 78.5114}}

This works because all Mathematica's arithmetic operators have a property called Listable, which means they automatically map over lists such as data[[All, 2]]. In this case the operator doing the mapping is Power.