HW03-solutions - vasquez (mpv244) HW03: Atomic Theory Part...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: vasquez (mpv244) HW03: Atomic Theory Part I shear (52375) 1 This print-out should have 27 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. Note the due date is Tuesday so you will get an answer key to study for the exam. A second homework will be posted tonight. 001 10.0 points Which color in the rainbow has the longest wavelength? 1. green 2. yellow 3. orange 4. red correct 5. blue Explanation: Ordered by wavelengths, blue < green < yellow < orange < red 002 10.0 points What is the correct order of decreasing en- ergy? 1. microwaves, visible light, x-rays, -rays, ltraviolet light 2. microwaves, visible light, ultraviolet light, x-rays, -rays 3. visible light, microwaves, x-rays, -rays, ltraviolet light 4. -rays, x-rays, ultraviolet light, visible light, microwaves correct 5. visible light, ultraviolet light, microwaves, x-rays, -rays Explanation: -rays > x-rays > ultraviolet light > visible light > microwaves 003 (part 1 of 2) 10.0 points When sodium is heated, a yellow spectral line whose energy is 3 . 37 10- 19 J/photon is produced. What is the frequency of this light? 1. none of above 2. 6 . 626 10- 34 Hz 3. 1 . 602 10- 19 Hz 4. 5 . 09 10 14 Hz correct 5. 3 . 10 8 Hz 6. 5 . 09 10- 34 Hz 7. 3 . 37 10 11 Hz 8. 3 . 37 10 19 Hz 9. 5 . 9 10- 7 Hz Explanation: E photon = 3 . 37 10- 19 J / photon = ? E photon = h = E photon h = 3 . 37 10- 19 J 6 . 626 10- 34 J s = 5 . 09 10 14 Hz 004 (part 2 of 2) 10.0 points What is its wavelength? 1. 6 . 626 10- 34 m 2. none of above 3. 1 . 602 10- 19 m 4. 3 . 10 8 m 5. 5 . 09 10 14 m 6. 5 . 9 10- 7 m correct Explanation: = ? c = vasquez (mpv244) HW03: Atomic Theory Part I shear (52375) 2 = c = 3 . 10 8 m/s 5 . 09 10 14 Hz = 5 . 9 10- 7 m 005 10.0 points What key result from the photoelectric effect showed that classical physics did not work on the atomic scale? 1. Light intensity and electron current were related. 2. All metals are reflective. 3. Different metals showed different behav- iors. 4. Radiation below a certain frequency, no matter how intense, would not cause electron emission. correct 5. The effect is not observed when a gas is introduced into the vacuum chamber. Explanation: When electromagnetic radiation (light) of sufficient minimum energy strikes a metal cathode, electrons are knocked off its sur- face, travel to an anode, and form a current through a circuit. Two important observations were: 1) Electrons can be ejected only if the light is sufficiently energetic. Electron ejection is independent of time or intensity. The mini- mum energy varies by element....
View Full Document

Page1 / 8

HW03-solutions - vasquez (mpv244) HW03: Atomic Theory Part...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online