Question

Which of the following molecular orbitals has two nodal planes?
(A) $\sigma 2s$
(B) $\pi {2_{py}}$
(C) ${\pi ^*}_{2py}$
(D) ${\sigma ^*}{2_{px}}$

Answer 1

When an atom joins together in a definite ratio to form a molecule. Different molecules have different shapes and properties. Different types of force of attraction occurs between the molecules.

Complete step by step answer:
When molecules are formed and in molecule’s different types of attraction occur. This force of attraction in between molecules totally depends on how much distance occurs between the molecules.
This type of force of attraction also known as van der waals forces. Nodal plane may be defined as the location at which the possibility of electrons finding that location is zero; that plane is known as nodal plane. When a hybrid orbital is formed from mixing of closely related orbitals having almost the same energy during hybridization, hybrid orbitals have different values of the nodal plane. In p orbital three orbitals are present they are $p_xp_yp_z$ and according to Hund's rule of maxmiplicity firstally three p orbital are not paired until three orbitals are singly distributed.
So in given examples ${\pi ^*}_{2py}$ here ${\pi ^*}$ means the bond is pi bond (this bond is formed by mixing of sidewise overlapping of antibonding orbitals) and $2py$ here it means two ${p_y}$ orbitals are overlapped sidewise and having two locations at which possibility of electrons finding on that location is zero that plane it means in ${\pi ^*}_{2py}$ have two nodal planes.
Hence option C is the correct option.

Note:
Different molecular orbitals have different shapes like s orbital is spherical, p orbital is dumbbell in shape and d orbital is double dumbbell shaped.
The value of the nodal plane in different orbital is different due to different shapes of orbitals and probability of finding an electron is different in different orbital.
Molecular orbital is also described as the nature of the electron is wave nature.