The energy of an electron in the first Bohr orbit of hydrogen atom is −2.18 × 10⁻¹⁸ J. Its energy in the third Bohr orbit is _______

Energy of Electron in Bohr Orbits | JEE Main PYQ | Structure of Atom

Q. The energy of an electron in the first Bohr orbit of hydrogen atom is −2.18 × 10⁻¹⁸ J. Its energy in the third Bohr orbit is ________.

A. One third of this value

B. Three times of this value

C. 1/9 th of this value

D. 1/27 of this value

Correct Answer: 1/9 th of this value

Explanation

According to Bohr model, energy of electron in hydrogen atom is given by:

E_n = −2.18 × 10⁻¹⁸ / n² J

For third Bohr orbit (n = 3):

E₃ = E₁ / 3² = E₁ / 9

Hence, energy in third Bohr orbit is 1/9 th of the energy in first Bohr orbit.

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