In an atom of hydrogen, where is the highest-energy electron located?

• A. In the 4f orbital
• B. In the 3d orbital
• C. In the 1s orbital
• D. In the 2p orbital

Answer: (C)

Verified step by step guidance

1. Recall that in a hydrogen atom, the energy of an electron depends primarily on the principal quantum number \(n\), where lower \(n\) means lower energy and higher \(n\) means higher energy.
2. Identify the principal quantum numbers for each orbital: 1s has \(n=1\), 2p has \(n=2\), 3d has \(n=3\), and 4f has \(n=4\).
3. Understand that the electron in hydrogen occupies the lowest energy orbital available, which is the 1s orbital with \(n=1\).
4. Recognize that orbitals with higher \(n\) values (like 2p, 3d, 4f) have higher energy levels and are unoccupied in the ground state of hydrogen.
5. Therefore, the highest-energy electron in a hydrogen atom is located in the 1s orbital, as it is the only electron and it occupies the lowest energy level.