A hydrogen atom is initially in its ground state. An external agent supplies just enough energy to place the electron directly in the third Bohr orbit without ionising the atom. How much energy must be supplied?
Options

Question

A hydrogen atom is initially in its ground state. An external agent supplies just enough energy to place the electron directly in the third Bohr orbit without ionising the atom. How much energy must be supplied?

Options

G1 Physics · Accepted Answer

For hydrogen, Eₙ = −13.6 ÷ n² eV. Ground-state energy: E₁ = −13.6 eV. Third-orbit energy: E₃ = −13.6 ÷ 9 ≈ −1.511 eV. Required excitation energy: ΔE = E₃−E₁ = −1.511−(−13.6) = 12.089 eV ≈ 12.09 eV. The corresponding excitation potential is numerically 12.09 V for a single electron charge. Correct option: B.