Question

p-orbitals of an atom in presence of magnetic field are:
A.Three-fold degenerate
B.Two-fold degenerate
C.Non-degenerate
D.None of these

Answer 1

Hint: When the magnetic is absent in p orbital, then energy of every level becomes same so p orbitals in absence of magnetic field starts working as degenerate orbitals. Similarly, if the p orbital degenerates in absence of magnetic current then in the presence of magnetic field, it remains the same.

Complete step by step answer:
In absence of magnetic field, the degeneracy of p− orbitals is 3. In presence of magnetic field, the degeneracy of orbitals stays the same if the orbitals can be interconverted that is converted back by symmetric operation like rotation, reflection etc. Since p-orbitals are similar to each other, they can be interconverted by symmetric rotation. Due to this, in presence of magnetic field also, the p-orbitals are three-fold degenerate. In covalent bonding, two atomic orbitals can collaborate to generate two “hybrid orbitals”. The hybrid orbitals have two energy levels. They are known as “bonding” and “antibonding” orbitals. Electrons go into the lower energy “bonding orbital”, resulting in chemical bonding. The p orbital that takes part in the bonding is clearly no longer the same as the other two p orbitals. It has become part of a system with different energy levels compared with the other two original p orbitals.

So the correct answer is option A

Note: The degeneracy of the orbital of a set will not be affected or influenced by the external field. If the orbitals will be converted back by symmetrical operation. P orbitals can also be converted by symmetrical operation as they are symmetrical to each other. F orbitals are of many different types so they are susceptible to external fields. In absence for magnetic fields p-orbitals have the same energy level and are degenerate orbitals.