Our energy supply comes mainly from fossil fuels, with nuclear power and renewable sources rounding out the mix. These sources originate mostly in our local star, the Sun. Electricity falls into its own category because it's an energy carrier and not a primary source.
Answer:b
Explanation:I believe it’s b I looked it up on google
DNA is made up of the individual units called Nucleotides.
Answer;
-Analytical chemistry - composition.
Environmental - impact of chemicals
Explanation;
-Analytical chemistry involves the qualitative and quantitative determination of the chemical components of substances. In qualitative analysis all the atoms and molecules present are identified, with particular attention to trace elements. In quantitative analysis the exact weight of each constituent is obtained as well.
Environmental chemistry is the study of the chemical and biochemical phenomena that occur in the environment.It relies heavily on analytical chemistry and includes atmospheric, aquatic, and soil chemistry.