What is the charge of an atom after it gains an electron during the formation of a bond?
a. one positive charge
b. two positive charges
c. two negative charges d. one negative charge

D. One negative charge

Explanation:

During the formation of a bond, if an atom gains an electron, after that it will be left with a negative charge compared to the atom before the bond is formed. This is because in these types of bonds, which are ionic bonds, there is a transfer of electrons between atoms, there will be one or more atoms that yield electrons that will be captured by another and other atoms that gain them, and the difference of charges produced by this transfer of electrons, will cause the union to occur due to the attraction between electrostatic forces.

If you have a neutral atom before joining, and it gains an electron to form a bond, it will have one electron more than its initial state (in the initial state, the number of protons and electrons is the same, because the atoms they are electrically neutral), so having an extra electron will make it have a negative charge, since there will be a difference between the number of protons and electrons that the atom possesses. This is why the correct answer is D.

In the case of response A and B, the atom could only remain positively charged if it loses electrons, but as in this case it wins, they are not correct.

The answer C is also not correct because only one electron wins, so that it is left with two negative charges, it should gain two electrons during the bond formation.