Final answer:
To convert absorbance to % transmittance, use the formula A = -log10(%T / 100). For an absorbance of 1.0, percent transmittance is calculated as 10%, meaning 90% of the light is absorbed.
Step-by-step explanation:
To calculate absorbance from percent transmittance (%T), the following formula is used:
A = -log10(%T / 100)
Here, A is the absorbance and %T is the percent transmittance. The percent transmittance is a measure of how much light passes through a sample compared to the incident light. A value of 100% transmittance indicates no light absorption by the sample. To express an absorbance value of 1.0 in terms of percent transmittance, we use the formula in reverse:
%T = 100 * 10^(-A)
Therefore, for an absorbance (A) of 1.0, the percent transmittance (%T) would be:
%T = 100 * 10^(-1.0)
%T = 10%
This implies that only 10% of the incident light is transmitted through the sample, and 90% is absorbed.