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Photoelectric Effect
| Term | Definition |
|---|---|
| Electromagnetic radiation | Energy composed of oscillating electric and magnetic fields |
| Electromagnetic spectrum | The range of EMR of all energies from radio waves at the low end of the the spectrum to the high end of the spectrum |
| How was light described in the 18th and 19th centuries? | As a wave because it showed wave-type behaviors |
| What are three behaviors of waves? | Reflect: light waves bounce off some surface Refract: light waves bend when they move from traveling through one substance to another. Diffract: light waves bend when they go through an opening. |
| What are the characteristics of waves | Wavelength Period Frequency Speed Intensity/amplitude |
| Wavelength | Distance of the top of one wave to the top of another |
| Period | Time for one complete wave to pass |
| Frequency | The number of waves that pass a given point in space in a specific amount of time |
| Speed | How fast a wave travels from one point to the other Dependent on wavelength and frequency |
| Intensity and amplitude | For light: brightness |
| Speed of light in a vacuum | 3.00 • 10^8 meters per second |
| What does EMR do when it is passed through a prism | Separates into a spectrum |
| What are emission spectra produced by | Light given off when a substance is excited by heat or electricity |
| What does emission spectra look like | Bright lines of color against a black background |
| How are absorption spectra formed | When light passes through a given substance |
| What does absorption spectra look like | A rainbow of colors broken by black lines |
| What are absorption and emission spectra characteristics of | The element that produced them |
| What happens when you combine a single element's absorption and emission spectra together? Why does this happen? | Forms a complete rainbow or spectrum; the absorption and emission spectrum are inverses of one another |
| Quantized | Being limited to specific values and no others |
| Photoelectric effect | When light shone on a metal the metal would eject electrons which it the metal was connected to a meter would display an electric current |
| What should light with more energy do | Eject more electrons |
| What does brighter light have | Greater amplitude |
| What should a brighter light have | More energy and eject more electrons |
| What does the color of light correspond to | Particular wavelength and frequency |
| Below the threshold frequency, what happened even though bright light was shown and more energy should be ejected | No electrons were ejected no matter how bright the light was |
| What happened at the threshold frequency | Electrons began to be ejected |