Question

Which of the following relations is correct?
A) Ist IE of C > Ist IE of B
B) Ist IE of C < Ist IE of B
C) IInd IE of C > IInd IE of B
D) Both B and C

Answer 1

In simple terms Ionization Energy (IE) is the measure of the difficulty that is faced in removing an electron from an atom or ion, or can be also be termed as the tendency of an ion or atom to surrender an electron. The loss of the electrons mostly happens in the ground state. To solve this question, we’ll first know about the trend of IE across the period in the periodic table.

Complete Step By Step Answer:
In more technical terms we can describe ionization energy as the minimum energy required to remove an outermost electron from an isolated gaseous atom or the minimum energy an electron has to absorb to come out from the influence of the nucleus. It is also described as the Ionization potential and is usually an endothermic process. The ionization energy gives us an idea of the strength of the chemical bonds and is measured in the units of electron volt (eV) or kJ/mol.
Generally, the First Ionization energy (the energy required to remove the first electron) increases as we move from left to right across a period in the periodic table. This is because the nuclear charge on an atom goes on increasing with the addition of electrons in the outermost orbital, and also decreases in size. Due to the decrease in the size, the attraction of electrons by the nucleus increases, due to which the electron is tightly held to the atom. Therefore, the energy required to remove the electron also increases.
Boron (B) and Carbon (C) belong to Period 2. Carbon comes after boron in the period, hence the ionization energy of Carbon will be more than that of Boron, because the size of Carbon is less than Boron.
Hence, we can say that ${1^{st}}I.E(Carbon) > {1^{st}}I.E(Boron)$
Option (A) is the correct answer.

Note:
The ionization energy decreases down the group, because the atomic radius increases and the atom becomes bigger. Hence due to increased atomic size and shielding of electrons, the attraction of nucleus and electrons decreases. The electrons are loosely bound and can be easily removed. The energy required would be less.