In the following question, Assertion (A) is given followed by a statement of Reason (R). Choose the correct answer.

Assertion (A): $$\pi\left(2 p_x\right), \pi\left(2 p_y\right), \pi^*\left(2 p_x\right), \pi^*\left(2 p_y\right)$$ molecular orbitals have one nodal plane each.

Reason $$(\mathrm{R})$$ : All the molecular orbitals formed by the sideways overlapping have one nodal plane.

Arrange the following in the decreasing order of their Dipole moments.

a. Chlorobenzene

b. 1,2-Dichlorobenzene

c. 1,3-Dichlorobenzene

d. 1,4-Dichlorobenzene.

Which of the following molecules does not exhibit dipole moment?

(i) CCl$$_4$$ (ii) CO$$_2$$ (iii) NH$$_3$$ (iv) CHCl$$_3$$ (v) H$$_2$$O (vi) CH$$_3$$$$-$$O$$-$$CH$$_3$$

Increasing order of bond order of oxygen and its ions is