Answer:
This question is incomplete
Explanation:
Experimentally, when trying to determine the concentration of an unknown sample of CuSO₄ with known absorbance, a standard curve is used. The standard curve is a scattered plot/graph in which known concentrations and there respective/corresponding absorbance are plotted on a "X and Y axis" graph (scattered plot). The absorbance is represented on the y-axis while the concentration is represented on the x-axis.
Once this known values are plotted on the standard curve, an unknown value (either absorbance or concentration) can be extrapolated from the curve. What is missing from the question is data required for the standard curve.
This question shows the absorbance of the CuSO₄ has been determined (most likely using spectrophotometer), the concentration could have been extrapolated from a standard curve.
An example of a standard curve is provided in the attachment for guidance.
Mesozoic, the era contained both large reptiles and small birds/mammals. It's interesting, coming from an evolutionary biology.
Hope this helped!
The answer is the first one.
Question number 2 the dna the answer is number 4 the last one
