Question

Rank the following elements in order of increasing ionization energy: Ge, Rb, S, Ne

Answer 1

order of increasing Ionization energy = Rb<Ge<S<Ne

Ionization energy is the amount of energy required to remove the most loosely bound valence shell electron from a gaseous atom.

the amount of energy required is depend upon the ease of extraction of valence electron.

electrons close to nucleus have more effective nuclear charge and hence they require more energy to remove and electrons which are away from nucleus possesses less effective nuclear charge and hence require less energy to remove.

Therefore, Ionization energy is indirectly proportional to the size of gaseous atom. more the size of gaseous atom less will be the energy required.

also, order of increasing size is Rb<Ge<S<Ne

larger atom require less energy and smaller atom require high energy. Here Rubidium is largest and Neon is smallest among them.