# One electron travels twice as fast as another which

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One electron travels twice as fast as another. Which has longer wavelength? 1. The slower one correct 2. The faster one 3. More information is needed. 4. The two have the same wavelength. Explanation: The twice-as-fast electron has twice the mo- mentum. By de Broglie’s formula, wavelength
EM waves and particles yeazell (58010) 3 is inversely proportional to momentum, so twice the momentum means half the wave- length. Thus the slower electron has the longer wavelength. 006 10.0points What is the uncertainty in the speed of a proton if it is desired to locate its position to within an uncertainty of x = 4 . 47 nm ? Planck’s constant is 6 . 63 × 10 34 J · s and the mass of the proton is 1 . 67 × 10 27 kg. Use the Heisenberg uncertainty principle, x p x h 4 π 0 0 - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 n = 4 n = 3 n = 2 n = 1 Energy (eV) Which of the following photon energies E γ could NOT be found in the emission spectra of this atom after it has been excited to the n = 4 state? Which of the following transitions will pro-
× 1 4 . 47 × 10 9 m = 7 . 06773 m / s . 007(part1of2)10.0points A hypothetical atom has four energy states as shown. duce the photon with the longest wavelength? 1. n = 4 to n = 3 correct 2. n = 2 to n = 1 3. n = 3 to n = 2 4. n = 4 to n = 1
009(part1of3)10.0points Consider just four of the energy levels in a certain atom, as shown in the diagram below.
n = 1 n = 2 n = 3 n = 4 How many spectral lines will result from all possible transitions among these levels? Which transition corresponds to the highest- frequency light emitted? Which transition corresponds to the lowest-frequency?
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