When radiometric dating is done on a rock sample, the rock's is determined.

comparative age

relative age

absolute age

sequential age

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

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

i might be wrong but i think its a. let me know if i’m right and have a good rest of your day!