Question

Arrange the following elements in increasing order of first ionization enthalpy:

Li, Be, B, C, N

Choose the correct answer from the options given below:

पर्याय

• Li < Be < C < B < N

• Li < Be < N < B < C

• Li < Be < B < C < N

• Li < B < Be < C < N

Answer 1

Li < B < Be < C < N

Explanation:

Ionization enthalpy refers to the minimal energy needed to remove the most loosely bound electron from an isolated gaseous atom.

Li, Be, B, C, and N are all elements that are classified in the second period of the modern periodic table. Atomic size decreases across the period from left to right, while effective nuclear charge increases. Consequently, ionization enthalpy also increases.

Be has more ionization enthalpy than B because its outer shell has all paired electrons, while boron has one unpaired electron.

The correct order of ionization enthalpy is Li < B < Be < C < N.