Bohr reasoned that the orbits of the electrons surrounding the nucleus must have a definite diameter. He determined that an electron could emit energy of one or two quanta, but not 1.5 or 3.2 quanta, as it fell to a lower energy level.
A ball bouncing from one step to another represents the motion of an electron as it falls from one energy level to another. The bottom of the starcase represents the lowest energy level within an atom.
Refer to the spectrum of hydrogen in a textbook. Each line of the spectrum represents one frequency of light, and therefore a certain energy (E=hv). This energy is determined by the movement of electrons between energy levels which are specific for each element. The same set of energy levels will always produce the same spectrum. When an electron falls from a higher to a lower energy level, a photon is emitted. The greater the difference in energy levels, the greater will be the energy of the light emitted. As an electron moves farther from the nucleus, it absorbs energy.
_________________ 1. According to the formula c=wavelength x frequency (v), when frequency gets larger, the wavelength, gets ________.
__________________2. Which light waves contain more energy, infrared or ultraviolet?
__________________ 3. Do microwave ovens, produce waves with a very short or very long wavelength compared to an X-Ray machine.
__________________ 4. Microwaves are high-energy waves that can be used for cooking. What equation can be used to show why a microwave has high energy?
__________________ 5. The smallest orbit of an electron is called its __________ state.
__________________ 6. The photoelectric effect was discovered and explained by ___________.
__________________ 7. The photoelectric effect confirmed the _________ nature of light.
__________________ 8. Ultraviolet radiation can be used to study atomic and molecular __________.
__________________ 9. Visible radiations are less destructive because they have less _________ than UV radiation.
__________________ 10. An electron is in a(n) ___________ state when it goes from a lower energy level to a higher energy level.
11. Draw a Picture of a Cathode Ray Tube
12. Draw the cathode ray on the picture to demonstrate its charge.
13. Explain your drawing. Include a description of the charge on an electron.
________________ 14. What scientist determined the charge on an electron?
________________ 15. What is the charge on an electron?
________________ 16. In 1932, Chadwick discovered a high energy particle with no charge and with the same mass as the proton. What are these particles called?
________________17. Frequency is measured in units called____.
_______________ 18. Planck proposed that light was given off in little packets called quanta or _____.
_______________ 19. The wavelength and frequency of light are related by the equation, c=______.