Which ion has a larger atomic radius, Cu+ or Cu2+? Explain your reasoning.

Video transcript

Hey everyone, we're asked to identify the ion that has a smaller radius. Cobalt with a plus two charge. Or cobalt with a plus three charge justify your answer Now as we've learned when it comes to our radius, the more electrons than an atom or an ion possesses, the bigger it is. So when we look at cobalt with a plus two charge, We know that the atomic number is 27. And if we subtract the two, we end up with 25 electrons. Now looking at cobalt with a plus three charge again, we have that atomic number of 27 and we subtract the three and we get 24 electrons. Now this is important because a positive charge essentially means that we have lost electrons. So cobalt with a plus three charge contains fewer electrons than cobalt with a plus two charge. So this means cobalt with a plus three charge will have that smaller radius. And the reason why is because electrons are removed from the outermost orbital, which results in an increase of the effective nuclear charge felt by the remaining electrons. Which essentially means we have that smaller radius. And this is going to be our final answer. Now, I hope that made sense. And let us know if you have any questions