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An electron in the ground state of the hydrogen atom has the orbital radius of 5.3 × 10 –11 m while that for the electron in third excited state is 8.48 × 10 –10 m. The ratio of the de Broglie wavelengths of electron in the ground state to that in excited state is

1. 4
2. 9
3. 3
4. 16

Correct answer: 4

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