begin mathsize 36px style A equals log open parentheses I subscript o over I close parentheses space end style

A = Absorbance ; Io = Intensity of the incident radiation ; I = Intensity of the transmitted radiation  

begin mathsize 36px style E subscript j equals fraction numerator h squared over denominator 8 straight pi squared straight I end fraction J left parenthesis J plus 1 right parenthesis end style

Ej = Rotational energy Level; I= Moment of Inertia; J= Rotational quantum number ; h = Plank's constant 

begin mathsize 48px style A equals epsilon c l end style

A = Absorbance ; ε = Molar absorption coefficient , Molar absorptivity  or Molar extinction coefficient c = Concentration ; l  = Path Length

begin mathsize 48px style log open parentheses T close parentheses space equals space epsilon c l end style

T= Transmittance ; ε = Molar Absorption Coefficient ; c = Concentration ; l = Path Length

begin mathsize 36px style x equals e to the power of negative fraction numerator B. h. c. J left parenthesis J plus 1 right parenthesis over denominator K subscript B T end fraction end exponent space semicolon space space bevelled N subscript j over N subscript 0 equals x space end style

 NJ = Number of molecule in J state ; N0 = Number of molecule in the ground state ( J= 0 ) ; K=Bolzmann Constant ; T = Temperature ; B = Rotational Constant; h = Plank Constant ; x=Relative Population; c = Velocity of light ; J = Rotational Quantum Number 

begin mathsize 36px style C subscript a H subscript b O subscript c N subscript d end style

CaHbOcN= Molecular Formula of Fragment ; a , b, c & d must be an positive integer or 0 (zero) 

Use this calculator to predict the molecular fragment obtained in a Mass Spectra.