Introduction:
When atoms gain or lose electrons, they form charged species called ions. In some cases, the resulting ions may have partially filled or empty orbitals, depending on the electronic configuration of the neutral atom. In this case, we will explore why nitrogen with a positive charge does not have an empty p orbital while carbon with a positive charge does have an empty p orbital.

Explanation:
1. Electronic Configuration:
The electronic configuration of neutral nitrogen (N) is 1s² 2s² 2p³, and neutral carbon (C) is 1s² 2s² 2p². When nitrogen gains a positive charge, it loses three electrons, resulting in 1s² 2s² 2p². On the other hand, when carbon gains a positive charge, it loses two electrons, leading to 1s² 2s² 2p³.

2. Formation of Ions:
When neutral nitrogen forms a cation, it loses electrons from the 2p orbital, specifically from the three p orbitals (px, py, and pz). Due to the loss of these electrons, the 2p orbitals are still partially filled with one electron each, and there is no empty p orbital. Therefore, a positively charged nitrogen ion does not have an empty p orbital.

On the other hand, when neutral carbon forms a cation, it loses electrons from the 2s orbital and one of the 2p orbitals. As a result, there is one remaining electron in the 2p orbital, leaving it empty. Hence, a positively charged carbon ion has an empty p orbital.

3. Stability and Hybridization:
The formation of ions involves the redistribution of electrons, resulting in changes in the electronic configuration. In the case of nitrogen, losing three electrons from the 2p orbital would require a significant amount of energy due to the relatively high stability of a half-filled p orbital. Therefore, nitrogen tends to prefer alternative forms of bonding, such as covalent bonding, rather than losing enough electrons to form a cation.

Carbon, on the other hand, readily forms cations by losing two electrons from the 2s and 2p orbitals. As a result, the empty p orbital in the positively charged carbon ion can participate in bonding with other atoms.

Conclusion:
In summary, when nitrogen gains a positive charge, it does not have an empty p orbital due to the stability associated with a half-filled p orbital. On the contrary, carbon with a positive charge has an empty p orbital, allowing it to form cations and participate in bonding. The electronic configuration and stability considerations play a crucial role in determining whether an ion has empty or partially filled orbitals.