3. How does changing the number of neutrons affect an atom?

The change of number of neutrons does not affect the charge of the atom. All it will affect is your average atomic mass which is the sum of protons and neutrons.

Explanation:  Hope this can help! ^^

It will change the isotopes.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides