Planck's constant is h = 6.6 × 10^-34 Js and the electron mass is 9.1 × 10^-31 kg. The speed of an electron whose de Broglie wavelength is 10^-10 is A) 6.6 × 10^-24 m/s. B) 3.8 × 10³ m/s. C) 7.3 × 10⁶ m/s. D) 10¹⁰ m/s.

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Quizplus · Accepted Answer

The de Broglie wavelength λ is given by λ = h/(mv), where h is Planck's constant, m is the mass of the electron, and v is its velocity. Solving for v gives v = h/(mλ). Substituting the given values, v = (6.6 × 10^-34 Js) / (9.1 × 10^-31 kg × 10^-10 m) = 7.3 × 10^6 m/s.

Planck's Constant Is H = 6