Why is the absorbance versus concentration curve for a substance rarely straight for all concentrations?

 In fact, it should be a straight line but the curve is rarely straight when the concentrations are either to high or to low.
This is due to the accuracy of the spectrometer. If concentration is too low, the amount of light transmitted is near 100% of the incident light and the electronic device can not measure it precisely. In an opposite way then the concentration is too high, the amount of light transmitted is too low and can not be measured accurately. However Beer-lambert law holds.

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer