Using only the periodic table arrange the following elements in order of increasing ionization energy

Question

boron, thallium, indium, aluminum

Answer 1

Answer:

Aluminum < Thallium < Indium < Boron

Short Explanation:

Ionization energy increases across a row (period) and decreases down the column (group) of the periodic table.

Ionization Energies:

Aluminum: 577.6 kJ/mol

Thallium= 595.4 kJ/mol

Indium: 1008.4 kJ/mol

Boron= 1139.9 kJ/mol

Thorough Explanation:

Ionization energy is the minimum amount of energy required to remove the most loosely bound electron, the valence electron, from an atom. It increases across the rows of the periodic table because it gets harder to remove an electron as the shell is becoming more full/more stable. It decreases as you go down the column because the new shell of electrons that is added is farther away from the nucleus of positive charges (the protons) and so is less tightly bound to the atom.