Emission spectra

• What are emission spectra produced by?

  Electrons emitting quanta of radiation
• What do energy levels in atoms or ions refer to?

  Orbitals where electrons occupy around the nucleus
• What is the lowest energy state of electrons called?

  Ground state
• What happens when atoms or ions absorb radiation?

  Electrons move to a higher energy level
• What are the fixed amounts of radiation absorbed by electrons called?

  Quanta
• What is the term for electrons that have moved to a higher energy level?

  Excited state
• How do electrons return to the ground state?

  By emitting quanta of energy as light
• What do the quanta of energy emitted equal?

  The gaps between two energy levels
• What is unique about the spectrum produced by emission spectra?

  It is unique to the atoms or ions being heated
• What is one use of flame emission spectroscopy?

  To identify elements in unknown substances
• How can materials scientists use emission spectroscopy?

  To check for impurities in materials
• How do astronomers use emission spectra?

  To identify elements in stars' light
• In medicine, what can be detected using emission spectra?

  Levels of sodium and potassium ions
• What do colored 'neon' lights use for their effect?

  Emission spectra of noble gases
• How can a forensic scientist identify metal ions in soil samples?

  • Use flame emission spectroscopy
  • Analyze color and intensity of emitted light
  • Compare results to known standards
• What are the steps involved when electrons absorb energy and emit light?

  1. Absorb fixed radiation (quanta)
  2. Move to a higher energy level (excited state)
  3. Emit energy as light when returning to ground state