1 / 8

Spectra

Spectra. White Light. Light from many colors mixes to form white light. Different colors have different wavelengths. Shorter wavelengths bend more through a prism. A diffraction grating combines many edges and acts like a prism. Emitted photon. Moving electron. Sources of Photons.

Download Presentation

Spectra

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Spectra

  2. White Light • Light from many colors mixes to form white light. • Different colors have different wavelengths. • Shorter wavelengths bend more through a prism. • A diffraction grating combines many edges and acts like a prism.

  3. Emitted photon Moving electron Sources of Photons • Accelerated electrons and atoms emit photons. • Photons can be reabsorbed as well.

  4. Temperature • Higher temperature means more energy. • Temperature is measured in kelvin (K). • Absolute zero: 0 K = -273 ºC = -459 ºF. • Room temperature: 300 K  20 ºC = 68 ºF. • Temperature of the Sun: 5800 K  6100 ºC  11,000 ºF • At high temperatures kelvin and centigrade are about the same.

  5. Heated objects give off electromagnetic waves. Higher temperature has more radiation A hot object gives off a spectrum of frequencies. Shifts based on temperature intensity high energy low energy frequency Radiation from Heat

  6. Radiation due a heated object is called blackbody radiation. Wien’s law relaters the temperature to the peak wavelength. intensity high energy low energy frequency Continuous Spectrum

  7. Atoms and Light • An atom is a nucleus surrounded by electrons. • An electron can be in specific energy states. • Change from a high to low energy state produces a photon. • Atoms can also absorb a photon to excite an electron.

  8. Discrete Spectrum • Each atom has its own set of energy levels. • Each atom generates photons at specific frequencies. • The pattern of frequencies (colors) identifies the atom. • Examples include neon or mercury lights. helium neon

More Related