What is the final, balanced equation this is formed by combining these two half reactions? click on picture!

Cu + NO₃⁻ + 2H⁺ → Cu²⁺ + NO₂⁻ + H₂O.

Explanation:

Cu → Cu²⁺ + 2e⁻                                      (1)

NO₃⁻ + 2e⁻ + 2H⁺ → NO₂⁻ + H₂O           (2)

So, the final balanced equation is:

Cu + NO₃⁻ + 2H⁺ → Cu²⁺ + NO₂⁻ + H₂O.

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.