Chemistry · S and p Block Elements

An excited state of an atom occurs when one or more electrons are promoted to higher energy orbitals. For scandium (Sc), the ground state electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹ 4s². In an excited state, an electron from the 4s orbital can be promoted to a higher energy level, such as the 3d orbital. This makes the 4s orbital relevant in the context of an excited state. Therefore, Option D (4s) correctly represents an excited state of scandium. The other options (2p, 3s, 3d, 3p) are either fully filled or do not involve the transition of electrons to higher energy levels as part of the excited state process.

The 2p orbitals are fully filled in the ground state of scandium and do not participate in the excitation of electrons to higher energy levels.

The 3s orbital is fully filled in the ground state and is not involved in the excitation of scandium to higher energy levels.

In the ground state, scandium already has an electron in the 3d orbital. An excited state involves electrons moving to higher energy levels than 3d, not remaining or moving to it.

An excited state of scandium involves moving an electron from the 4s orbital to a higher energy orbital, such as 3d, making the 4s orbital involved in the excited state configuration.

The 3p orbitals are fully filled in the ground state of scandium and do not play a role in the excited state electron transitions.