Chapter 9 Test Review

Question

Which is larger, K or Rb? Why?

Answer 1

K and Rb are both in group 1 so they both have 1 electrons in the outer shell. Looking at the period, we see that K is in period 4 and Rb is in period 5. This tells us that Rb has more shells and so it would have a larger atomic radius than would K (n = 5 vs. n = 4).