Which statement describes Linus Pauling's contribution to the understanding of DNA structure?

Having first discovered the spiral shape of proteins, Linus Pauling used x-ray technology to hypothesize that the DNA molecule consisted of two consistently spaced strands that formed a spiral shape.

Linus Pauling studied DNA base pairing.

Having originally studied proteins, Pauling proposed that DNA was a three-chained helix with a sugar-phosphate backbone at the center and bases sticking out from the backbone.

Linus Pauling conducted experiments to prove that DNA carried genetic information.

Having originally studied proteins, Pauling proposed that DNA was a three-chained helix with a sugar-phosphate backbone at the center and bases sticking out from the backbone. thats what i put

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation:

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.