AP Physics 2 Flashcards: Emission And Absorption Spectra

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This deck focuses on Emission And Absorption Spectra, giving you a quick way to review the definitions, rules, and examples that matter most for AP Physics 2.

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Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is an emission spectrum?

Answer: A spectrum of frequencies emitted by an atom or molecule. Shows specific wavelengths of light emitted when electrons drop to lower energy levels.

Flashcard 2: Identify the instrument used to view spectra.

Answer: Spectroscope. Optical instrument that disperses light into component wavelengths for observation.

Flashcard 3: What does a spectrometer measure?

Answer: Intensity of light at different wavelengths. Device separates and measures light intensity across electromagnetic spectrum.

Flashcard 4: State the condition for observing an emission spectrum.

Answer: Excited electrons fall to lower energy levels. Energy release during electron transitions produces characteristic photons.

Flashcard 5: State the condition for observing an absorption spectrum.

Answer: Electrons absorb energy and move to higher levels. Energy absorption promotes electrons to higher quantum states.

Flashcard 6: What type of light source is ideal for observing a continuous spectrum?

Answer: Incandescent bulb or blackbody radiator. Thermal sources emit broad, continuous wavelength distribution.

Flashcard 7: What is the Balmer series associated with?

Answer: Emission spectrum of hydrogen. Series of visible lines from electron transitions to $n=2$ level.

Flashcard 8: Identify the term: spectrum with bright lines on dark background.

Answer: Emission spectrum. Bright lines indicate emission of specific wavelengths against dark background.

Flashcard 9: What type of light source is ideal for observing a continuous spectrum?

Answer: Incandescent bulb or blackbody radiator. Thermal sources emit broad, continuous wavelength distribution.

Flashcard 10: What type of spectrum is typically used in chemical analysis?

Answer: Both emission and absorption spectra. Combined techniques provide comprehensive elemental and quantitative analysis.

Flashcard 11: What is a spectrograph?

Answer: An instrument that records a spectrum photographically. Device that captures and records spectral data permanently for analysis.

Flashcard 12: Identify the spectrum: Sunlight passing through Earth's atmosphere.

Answer: Absorption spectrum. Atmospheric gases absorb specific wavelengths from continuous sunlight.

Flashcard 13: What is quantified by the intensity of spectral lines?

Answer: The concentration of elements. Line intensity correlates with number of atoms present.

Flashcard 14: What is a spectrograph?

Answer: An instrument that records a spectrum photographically. Device that captures and records spectral data permanently for analysis.

Flashcard 15: Which spectrum is produced by incandescent light bulbs?

Answer: Continuous spectrum. Hot tungsten filament produces thermal radiation across all visible wavelengths.

Flashcard 16: What is the primary use of emission spectra in laboratories?

Answer: To identify elements present in a sample. Bright emission lines reveal elemental composition through characteristic wavelengths.

Flashcard 17: What feature distinguishes a bright-line spectrum?

Answer: Bright lines indicating emitted wavelengths. Emission spectrum shows bright lines against dark background.

Flashcard 18: What is the result of electrons transitioning between energy levels?

Answer: Emission or absorption of photons. Energy differences between levels determine photon wavelength emitted or absorbed.

Flashcard 19: What type of spectrum does a hot, dense object emit?

Answer: Continuous spectrum. Dense objects emit all wavelengths continuously due to thermal motion.

Flashcard 20: What is an absorption spectrum?

Answer: A spectrum showing dark lines or bands due to absorption of light. Occurs when electrons absorb specific wavelengths, creating gaps in continuous spectrum.

Flashcard 21: What is the significance of the Rydberg formula?

Answer: Calculates wavelengths of spectral lines of hydrogen. Mathematical formula predicting hydrogen spectral line wavelengths accurately.

Flashcard 22: What is the purpose of using a monochromator in spectroscopy?

Answer: To isolate specific wavelengths of light. Device selects narrow wavelength bands from broader spectrum.

Flashcard 23: What is the purpose of using a monochromator in spectroscopy?

Answer: To isolate specific wavelengths of light. Device selects narrow wavelength bands from broader spectrum.

Flashcard 24: What type of spectrum is observed when light passes through a cool gas?

Answer: Absorption spectrum. Cool gas atoms absorb specific wavelengths from continuous background light.

Flashcard 25: State the condition for observing an emission spectrum.

Answer: Excited electrons fall to lower energy levels. Energy release during electron transitions produces characteristic photons.

Flashcard 26: Which spectrum is used to identify elements in stars?

Answer: Absorption spectrum. Dark absorption lines reveal elemental composition of stellar atmospheres.

Flashcard 27: State the condition for observing an absorption spectrum.

Answer: Electrons absorb energy and move to higher levels. Energy absorption promotes electrons to higher quantum states.

Flashcard 28: What is the Paschen series associated with?

Answer: Infrared emission spectrum of hydrogen. Series of IR lines from electron transitions to $n=3$ level.

Flashcard 29: What is the importance of spectral lines?

Answer: They identify elements and compounds. Each element produces unique spectral fingerprint for identification.

Flashcard 30: What type of spectrum does a hot, low-density gas emit?

Answer: Emission spectrum. Low-density gas atoms emit discrete wavelengths when electrons transition downward.

Flashcard 31: What type of spectrum results from a prism dispersing sunlight?

Answer: Continuous spectrum. Prism disperses white light into complete rainbow without gaps.

Flashcard 32: What type of spectrum does a hot, dense object emit?

Answer: Continuous spectrum. Dense objects emit all wavelengths continuously due to thermal motion.

Flashcard 33: In what type of spectrum do Fraunhofer lines appear?

Answer: Absorption spectrum. Dark lines in solar spectrum discovered by Joseph von Fraunhofer.

Flashcard 34: What feature distinguishes a bright-line spectrum?

Answer: Bright lines indicating emitted wavelengths. Emission spectrum shows bright lines against dark background.

Flashcard 35: Which spectral lines are visible when sodium vapor is heated?

Answer: Bright yellow lines. Sodium's characteristic D-lines appear as intense yellow doublet.

Flashcard 36: What is the importance of spectral lines?

Answer: They identify elements and compounds. Each element produces unique spectral fingerprint for identification.

Flashcard 37: Which spectral lines are visible when sodium vapor is heated?

Answer: Bright yellow lines. Sodium's characteristic D-lines appear as intense yellow doublet.

Flashcard 38: What is the result of electrons transitioning between energy levels?

Answer: Emission or absorption of photons. Energy differences between levels determine photon wavelength emitted or absorbed.

Flashcard 39: What is the Balmer series associated with?

Answer: Emission spectrum of hydrogen. Series of visible lines from electron transitions to $n=2$ level.

Flashcard 40: What type of spectrum results from a prism dispersing sunlight?

Answer: Continuous spectrum. Prism disperses white light into complete rainbow without gaps.

Flashcard 41: What is an emission spectrum?

Answer: A spectrum of frequencies emitted by an atom or molecule. Shows specific wavelengths of light emitted when electrons drop to lower energy levels.

Flashcard 42: What region of the electromagnetic spectrum do Balmer lines appear in?

Answer: Visible region. Balmer series produces visible light from hydrogen atom transitions.

Flashcard 43: Identify the term: spectrum with dark lines on bright background.

Answer: Absorption spectrum. Dark lines indicate absorption of specific wavelengths from continuous spectrum.

Flashcard 44: What is the primary difference between emission and absorption spectra?

Answer: Emission shows bright lines; absorption shows dark lines. Emission adds light at specific wavelengths; absorption removes it.

Flashcard 45: What causes the dark lines in an absorption spectrum?

Answer: Absorption of specific wavelengths by a substance. Electrons absorb photons of specific energies, removing those wavelengths from spectrum.

Flashcard 46: What is the Lyman series associated with?

Answer: Ultraviolet emission spectrum of hydrogen. Series of UV lines from electron transitions to $n=1$ ground state.

Flashcard 47: What region of the electromagnetic spectrum do Balmer lines appear in?

Answer: Visible region. Balmer series produces visible light from hydrogen atom transitions.

Flashcard 48: What does a spectrometer measure?

Answer: Intensity of light at different wavelengths. Device separates and measures light intensity across electromagnetic spectrum.

Flashcard 49: Identify the term: spectrum with bright lines on dark background.

Answer: Emission spectrum. Bright lines indicate emission of specific wavelengths against dark background.

Flashcard 50: Identify the instrument used to view spectra.

Answer: Spectroscope. Optical instrument that disperses light into component wavelengths for observation.

Flashcard 51: Which spectrum is used in neon signs?

Answer: Emission spectrum. Excited gas atoms emit characteristic colors when electrons drop energy levels.

Flashcard 52: What is the Paschen series associated with?

Answer: Infrared emission spectrum of hydrogen. Series of IR lines from electron transitions to $n=3$ level.

Flashcard 53: What is quantified by the intensity of spectral lines?

Answer: The concentration of elements. Line intensity correlates with number of atoms present.

Flashcard 54: What is the primary difference between emission and absorption spectra?

Answer: Emission shows bright lines; absorption shows dark lines. Emission adds light at specific wavelengths; absorption removes it.

Flashcard 55: What is the role of a diffraction grating in spectroscopy?

Answer: To separate light into its component wavelengths. Grating diffracts light into distinct wavelengths for spectral analysis.

Flashcard 56: Identify the region of the electromagnetic spectrum used in X-ray spectroscopy.

Answer: X-ray region. High-energy X-rays probe inner electron shells of atoms.

Flashcard 57: Identify the spectrum: Sunlight passing through Earth's atmosphere.

Answer: Absorption spectrum. Atmospheric gases absorb specific wavelengths from continuous sunlight.

Flashcard 58: Which spectrum is used in neon signs?

Answer: Emission spectrum. Excited gas atoms emit characteristic colors when electrons drop energy levels.

Flashcard 59: Which spectrum is used to identify elements in stars?

Answer: Absorption spectrum. Dark absorption lines reveal elemental composition of stellar atmospheres.

Flashcard 60: What is the primary use of absorption spectra in astronomy?

Answer: To determine the composition of stars and planets. Spectral lines act as fingerprints identifying specific elements remotely.

Flashcard 61: Identify the region of the electromagnetic spectrum used in X-ray spectroscopy.

Answer: X-ray region. High-energy X-rays probe inner electron shells of atoms.

Flashcard 62: What type of spectrum is observed when light passes through a cool gas?

Answer: Absorption spectrum. Cool gas atoms absorb specific wavelengths from continuous background light.

Flashcard 63: What is the Lyman series associated with?

Answer: Ultraviolet emission spectrum of hydrogen. Series of UV lines from electron transitions to $n=1$ ground state.