Based on their locations in the periodic table, which of these elements would you expect to have the greatest atomic radius?

Cesium have the greatest atomic radius .

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.