ACE PRACTICE TEST Chapter 7, Quiz 1

Transcription

1 ACE PRACTICE TEST Chapter 7, Quiz 1 1. Electromagnetic radiation is characterized by all but one of the following properties. A. velocity B. amplitude C. charge D. frequency E. wavelength 2. Which of the following frequencies of electromagnetic radiation has the longest wavelength? A. 1 kilohertz B. 1 dekahertz C. 1 terahertz D. 1 gigahertz E. megahertz 3. The frequency of one type of electromagnetic radiation is 50 megahertz. What is its wavelength in meters? A B. 1.5 C. 1.7 D. 6.0 E What is the wavelength in meters of electromagnetic radiation with a frequency of 1.0 hertz? A B C. 1.0 D E Calculate the wavelength in meters of electromagnetic radiation with a frequency of hertz. A B C D E The wavelength of blue light is approximately meters. Calculate the frequency of blue light in hertz. A B C D E

2 7. X-rays are used extensively in medicine to detect a variety of internal health problems. Calculate the frequency in hertz of an x-ray that has a wavelength of 1.1 angstrom. A B C D E Sodium vapor lamps are becoming a common sight along city streets. They are frequently found at intersections and exhibit a yellowish hue. The frequency of this light is hertz. Calculate the wavelength of this sodium light in meters. A B C D E The period T is the time it takes one wavelength to go through a point in space. According to this definition, period (T) and frequency (v) should be related in the following way: A. v = 1/T B. v = T C. T = v/c D. c = T v E. T = c/v 10. The frequency of electromagnetic radiation increases as its wavelength gets longer. A. true B. false 11. Which of the following types of electromagnetic radiation has the highest frequency? A. gamma rays B. red light C. blue light D. microwaves E. x-rays 12. Which of the following types of electromagnetic radiation has the longest wavelength? A. infrared B. red light C. gamma rays D. green light E. radio waves

3 13. Light is best described by A. its wave properties B. its particle properties C. both its wave and particle properties D. neither wave nor particle properties 14. Which famous scientist introduced the formula that describes quantization of energy? A. Bohr B. Heisenberg C. de Broglie D. Planck E. Davisson 15. Quanta of light are often called photons and have some of the characteristics of particles. Which famous scientist is said to have introduced the concept of quantized light? A. Bohr B. Einstein C. de Broglie D. Germer E. Davisson 16. Calculate the energy in joules of a photon of red light that has a wavelength of 700 nm. A B C D E Which of the following wavelengths of electromagnetic radiation is the highest in energy? A. 700 mm B. 100 nm C. 200 nm D. 700 nm E. 20 nm 18. What is the energy in joules of a photon that has a frequency in the gamma radiation range of the electromagnetic spectrum? Use a wavelength of m for gamma radiation. A B C D E

4 19. A 6.00 g sample of carbon is sealed inside a closed container. The carbon is vaporized by exposure to electromagnetic radiation with a wavelength of 150 nm. If each carbon atom absorbs a single photon of energy, how many joules of energy are needed to vaporize the entire 6.00 g sample of carbon? A B C D E Carbon emits light at a wavelength of 150 nm. The total amount of energy emitted by a sample is J. Assume that each carbon atom emits one single photon. Calculate the number of carbon atoms present in the sample. A B C D E A photon with an energy of J strikes an electron. All of the photon energy is converted into electron kinetic energy. What velocity, in m/s, will the electron have? Assume the electron is initially at rest. A B C D E As the energy of electromagnetic radiation increases A. the frequency decreases B. the wavelength increases C. both the frequency and the wavelength decrease D. both the frequency and the wavelength increase E. the frequency increases and the wavelength decreases 23. Compare the properties of the blue end of the visible spectrum with the red end of the visible spectrum. The blue end A. is higher in energy than the red end B. has a lower frequency than the red end C. has a longer wavelength than the red end D. all of the above are correct E. none of the above is correct

5 24. What is observed when the light emitted by a heated gas is dispersed through a prism? A. a continuous band of color B. ultraviolet light C. only blue light D. no light at all E. distinct lines of different colors 25. According to the Bohr model, electrons can have only specific energy values in an atom. A. true B. false 26. Emission of light from an atom occurs when an electron A. moves up one energy level B. climbs up two energy levels C. moves around the nucleus at an increased speed D. moves from a higher to a lower energy level E. gains a photon as it goes from a higher to a lower energy level 27. Absorption of light by atoms of an element occurs when A. photons are absorbed by neutrons B. photons are absorbed by protons that climb up in quantized energy levels C. photons are absorbed by electrons that climb up in quantized energy levels D. photons are produced by electrons that climb up in quantized energy levels E. photons are produced by protons that climb up in quantized energy levels 28. The Balmer equation can be used to calculate the wavelengths of the spectral lines in the visible region of the electromagnetic spectrum for the H atom. These lines are called the Balmer series and are produced by electron transitions from higher energy levels to the n = 2 energy level. Balmer's equation in terms of the frequency of the spectral lines is: v = s -1 (1/22-1/n 2 ), where v is the frequency of the line and n is the higher energy level. Using the Balmer equation, calculate the wavelength of light in nm for the transition from n = 5 to n = 2. A. 434 B C D. 365 E The Lyman series, like the Balmer series, is the series of spectral lines produced by electron transitions in the hydrogen atom. In the Lyman series, the spectral lines are in the ultraviolet region of the electromagnetic spectrum, and they are produced by transitions from higher energy levels to the n = 1 level. For the Lyman series, the frequency of the lines can be expressed by the following equation: v = s -1 (1/12-1/n 2 ). Calculate the wavelength in nm required to promote an electron from n = 1 to n = 4. A. 364 B. 911 C D E. 182

6 30. The visible spectrum covers the range between approximately 400 and 700 nm. Using the equation for the Balmer series given below, calculate the wavelength in nm of the transition from n = 2 to n = 7. v = s -1 (1/22-1/n 2 ) A. 365 B. 335 C. 852 D. 660 E The Balmer series lies primarily in what region of the electromagnetic spectrum? A. infrared B. microwave C. near ultraviolet D. x-ray E. visible 32. Ionization energy is the energy needed to remove an electron from an atom. Removal of an electron from an atom corresponds to moving the electron to the n = infinity energy level. Calculate the ionization energy in kj for a mole of hydrogen atoms that are in the n = 2 energy level. A. 328 B C. 654 D. 145 E I have absolutely no idea what this question was supposed to be, but here are your possible choices. Pick one and see if you are right! A. from n = 3 to n = 2 B. from n = 1 to n = 5 C. from n = 4 to n = 2 D. from n = 1 to n = 2 E. from n = 5 to n = Not a clue. Choose wisely. A. from n = 5 to n = 1 B. from n = 2 to n = 4 C. from n = 3 to n = 2 D. from n = 2 to n = 3 E. from n = 3 to n = Ditto. A. from n = 4 to n = 1 B. from n = 1 to n = 5 C. from n = 4 to n = 3 D. from n = 2 to n = 4 E. from n = 1 to n = 2

7 36. What is the difference in energy between two of the energy levels of an atom if the atom absorbs light with a wavelength of 530 nm? A J B J C J D J E J 37. Calculate the wavelength in meters associated with a proton that travels at a velocity of 0.10 c (one-tenth the speed of light). A B C D E A massive particle has a velocity equal to 0.10 c (one-tenth the speed of light) and a wavelength of m. Calculate the mass of the particle in kg. A B C D E An electron has a wavelength of m. Calculate the velocity of the electron in m/s. A B C D E What is the wavelength in meters of an electron that has a velocity equal to the escape velocity of the Earth? Escape velocity equals 25,000 mph. A B C D E

8 Key C 2. C 3. D 4. B 5. A 6. D 7. C 8. D 9. A 10. B 11. A 12. E 13. C 14. D 15. B 16. E 17. E 18. B 19. C 20. D 21. A 22. E 23. A 24. E 25. A 26. D 27. C 28. A 29. D 30. E 31. E 32. A 33. A 34. D 35. B 36. E 37. E 38. B 39. D 40. E