Which one of the following about an electron occupying the 1s orbital in a hydrogen atom is incorrect? (Bohr's radius is represented by a0 )
(A)The probability density of finding the electron is maximum at the nucleus
(B)The electron can be found at a distance 2a0 from the nucleus
(C)The 1s orbital is spherically symmetrical
(D)The total energy of the electron is maximum when it is at a distance a0 from the nucleus✓ Correct
Answer: (D)
Solution
For the hydrogen 1s orbital the probability density ψ2 is greatest at the nucleus and decreases smoothly with distance, the orbital is spherically symmetrical, and the electron has a finite though diminishing probability of being found at any distance, including 2a0. The total energy of the bound electron, however, is a fixed quantity (−13.6eV) set by its quantum state and does not depend on where the electron happens to be, so it does not become maximum at a distance a0. The statement claiming the energy is maximum at a0 is the incorrect one.
JEE Main · 2025 · 04 Apr 2025 · Shift 1 · Single correct option