Question

Which set correctly orders the atoms from highest to lowest ionization energy?

a) Li, Be, B
b) N, O, F
c) Cs, Ba, Sr
d) Cl, Br, I

Answer 1

The set that orders atoms from highest to lowest ionization energy is N, O, F, as ionization energy increases across a period in the Periodic Table due to increasing nuclear charge.

Step-by-step explanation:

The set that correctly orders atoms from the highest to lowest ionization energy is (b) N, O, F. Ionization energy tends to increase across a period (from left to right) due to increasing nuclear charge without any additional shielding from inner electron shells.

It also tends to decrease down a group (top to bottom) due to increased distance from the nucleus and increased shielding by inner electron shells. Therefore, within the same period, as we move from nitrogen (N) to oxygen (O) to fluorine (F), the ionization energy increases. The general trend in the Periodic Table shows that fluorine has a higher ionization energy than oxygen, which in turn has a higher ionization energy than nitrogen within the same period.