Practice question

MCQ

Question

An electron in the fourth orbit of a hydrogen atom has a velocity of 5.475 × 10⁵ m s⁻¹. What is its de Broglie wavelength? (h = 6.626 × 10⁻³⁴ J s, mₑ = 9.1 × 10⁻³¹ kg)

Options

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1.33 × 10⁻⁹ m Correct 6.65 × 10⁻¹⁰ m 2.66 × 10⁻⁹ m 9.98 × 10⁻¹⁰ m

Explanation

λ = h/(mv) ≈ 1.33×10⁻⁹ m.

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