Ch. 37 - Early Quantum Theory and Models of the Atom
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Problem 70
A beam of 125-eV electrons is scattered from a crystal, as in X-ray diffraction, and a first-order peak is observed at θ = 43°. What is the spacing between planes in the diffracting crystal? (See Section 35–11.)
Problem 85
A flashlight emits 2.8 W of light. As the light leaves the flashlight in one direction, a reaction force is exerted on the flashlight in the opposite direction. Estimate the size of this reaction force.
Problem 91
At what temperature would the average kinetic energy (Chapter 18) of a molecule of hydrogen gas (H₂) be sufficient to excite a hydrogen atom out of the ground state?