Physics SL
5
Chapters
329
Notes
Theme A - Space, Time & Motion
Theme B - The Particulate Nature Of Matter
Theme C - Wave Behaviour
Theme D - Fields
Theme E - Nuclear & Quantum Physics
Physics SL
Theme E - Nuclear & Quantum Physics
Unveiling Sunlight's Mysteries: The Story Of Emission & Absorption Spectra
695 words
4 mins read
Last edited on 5th Nov 2024
Table of content
Spectra Basics - A Blast from the Past 🌈
- Sunlight has a continuous spectrum.
- William Wollaston (1802): Spotted weird dark lines in the Sun's spectrum.
- Joseph von Fraunhofer (1814): Used a diffraction grating to see these lines, known as Fraunhofer lines. They're part of the absorption spectrum.
- Historical tidbit: Studying light isn't new! Romans to Europeans around the 16th century all looked at light from hot objects. They used prisms to spread sunlight into a rainbow. Still how we do it today!
Seeing Spectra in Action 🔥
- Create light: Pass electricity through low-pressure gas OR heat a substance.
- Light's atoms emit electromagnetic radiation.
- This radiation hits a diffraction grating or prism, splitting into different wavelengths. (Think rainbow!)
- Observe with a telescope or screen.
Sun’s Continuous Spectrum 🌞
- Result of interactions between all atoms in the Sun's hot dense gas.
- Low gas pressure = spectrum shows distinct lines. These are emission line spectra.
- Fun fact: Every element has a unique emission line spectrum!
Photon Business 💡
- Emission spectra are formed when atoms give off light photons during energy shifts.
- These photons come as discrete energy packets - quanta (one is a quantum).
- Energy of a photon, E = hf (h is the Planck constant, f is the photon's frequency).
- Planck’s constant, \(h = 6.63 × 10^{-34} Js.\)
- Convert energy equation with wavelength (λ) = E= \(\frac {hc}{λ}\)hc (c is the speed of electromagnetic waves).
Atomic Party! 🎉
- Atoms in solids, liquids, & high-pressure gases emit bands of colors when excited.
- In solids, these bands blend, showing no distinct colors. Why? Closely packed atoms influence each other’s energy states.
Unlock the Full Content! 
Dive deeper and gain exclusive access to premium files of Physics SL. Subscribe now and get closer to that 45 🌟
Physics SL
Theme E - Nuclear & Quantum Physics
Unveiling Sunlight's Mysteries: The Story Of Emission & Absorption Spectra
695 words
4 mins read
Last edited on 5th Nov 2024
Table of content
Spectra Basics - A Blast from the Past 🌈
- Sunlight has a continuous spectrum.
- William Wollaston (1802): Spotted weird dark lines in the Sun's spectrum.
- Joseph von Fraunhofer (1814): Used a diffraction grating to see these lines, known as Fraunhofer lines. They're part of the absorption spectrum.
- Historical tidbit: Studying light isn't new! Romans to Europeans around the 16th century all looked at light from hot objects. They used prisms to spread sunlight into a rainbow. Still how we do it today!
Seeing Spectra in Action 🔥
- Create light: Pass electricity through low-pressure gas OR heat a substance.
- Light's atoms emit electromagnetic radiation.
- This radiation hits a diffraction grating or prism, splitting into different wavelengths. (Think rainbow!)
- Observe with a telescope or screen.
Sun’s Continuous Spectrum 🌞
- Result of interactions between all atoms in the Sun's hot dense gas.
- Low gas pressure = spectrum shows distinct lines. These are emission line spectra.
- Fun fact: Every element has a unique emission line spectrum!
Photon Business 💡
- Emission spectra are formed when atoms give off light photons during energy shifts.
- These photons come as discrete energy packets - quanta (one is a quantum).
- Energy of a photon, E = hf (h is the Planck constant, f is the photon's frequency).
- Planck’s constant, \(h = 6.63 × 10^{-34} Js.\)
- Convert energy equation with wavelength (λ) = E= \(\frac {hc}{λ}\)hc (c is the speed of electromagnetic waves).
Atomic Party! 🎉
- Atoms in solids, liquids, & high-pressure gases emit bands of colors when excited.
- In solids, these bands blend, showing no distinct colors. Why? Closely packed atoms influence each other’s energy states.
Unlock the Full Content!
Dive deeper and gain exclusive access to premium files of Physics SL. Subscribe now and get closer to that 45 🌟
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