The Electrons in a Beam Are Moving at 18 M/s

question 66

Short Answer

The electrons in a beam are moving at 18 m/s. (m_electron = 9.11 × 10^-31 kg, h = 6.626 × 10^-34 J ∙ s)
(a) What is its de Broglie wavelength these electrons?
(b) If the electron beam falls normally on a diffraction grating, what would have to be the spacing between slits in the grating to give a first-order maximum at an angle of 30° with the normal to the grating?

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