So atomic numbers indicate the number of protons, which are positively ( + ) charged, while electrons are negatively ( - ) charged. Together, protons and electrons cancel each other out to create neutral energy.
Now with 34 protons and 36 electrons in this ion, there are going to be 34 protons and 34 electrons that will come together and become neutral energy. However, we will be left with 2 electrons in this ion. This can be represented as a -2 charge, or D.
