Nucleic acids are hydrocarbons that also contain which other element?

Nucleic acids are hydrocarbons that also contain nitrogen, phosphorus and oxygen elements. 
Hydrocarbons are long chains of carbon that have additional bonds exclusively with hydrogen atoms. They are hydrophobic, or not soluble in water. Nucleic acids are macromolecules that are made of units called nucleotides, they are mainly in two forms; the RNA and and the DNA. Both the RNA and DNA have a pentose sugar, a phosphate, and a nitrogen containing base. 

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Yes it would be a physical change.