The chemical element has a role in both transfer of energy as well as in the structure of nucleic acids.

Phosphorous

Explanation:

Phosphorous is used in nucleotide formation. When nucleoside is linked to a phosphate group, then nucleotide is formed. The nucleotides form the basic building block of the DNA and RNA. The DNA and RNA are together known as nucleic acid.

Nucleotides which are involved in energy transfer are ATP and GTP.  

These molecules contain three phosphate group and store energy in the form of phosphate bonds. When phosphate bond is broken, energy is released.

Therefore, the chemical element which has role in both energy transfer and structure of nucleic acid is phosphorous.

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b