Question

Which elements in the second period will have the lowest and highest ionization energies? Explain.

Answer 1

• Ionization energy is the amount of energy required to remove the electron from the atom.
• The second period consists of 8 elements, namely- Lithium (Li), Beryllium (Be), Boron (B), Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F) and Neon (Ne).
• In the periodic table, the ionization energy increases from left to right in a period because the electrons are added in the same shell, which increases the nuclear charge between the nucleus and the electrons. Thus, it becomes difficult to remove the electron from the valence shell.
• So, the order of ionization energy in the second period is Li < B < Be < C < N < O < F < Ne.
• Therefore, in the second period, Lithium has the lowest, and Neon has the highest ionisation energy.
• Note: Berrylium has high ionisation energy than Boron because it has completely filled shells.