What is the atmospheric layer with the lowest density? ?

The Exosphere

Explanation:

The Exosphere is the farthest away from the Earth and the least dense. Going towards the Earth a space ship would pass through the Ionosphere, then the Stratosphere where high flying airplanes can be found, and finally closest to the Earth is the Troposphere which is the thickest layer where all our weather takes place.

the backbone of the dna and rna compound is sugar phosphate.

answer/// wohler;