The optical density $($absorbances$)$ of $4$ different molar concentrations of the protein Bovine Serum Albumin $($BSA$)$ was measured at $280$ nm $($shown in graph$).$

A$.$ What is the molar extinction coefficient of BSA at $280nm?$

B$.$ Is it valid to use this extinction coefficient to determine the concentration of a BSA sample that is measured at a wavelength of $260$ nm$?$

C$.$ What property of proteins allows it to absorb electromagnetic energy in the UV range?

The electronic resistance of a solid material is given by $R={}^{**}\frac{L}{A},$ with units of $($ohms$).$

A$.$ State what the three variables, $,L,$ and A represent, and give the units for each variable.

B$.$ Is the resistance, $R,$ an intensive or extensive property of the solid? $($Explain briefly$).$

C$.$ Is the resistance, $R,$ a function of temperature?

Give one example of each type of interaction $($elastic and inelastic$).($Plea$$e give only one example each. If more than one example per interaction are given, all answered will be marked wrong!$)$ No explanation necessary.