Red solutions absorb green light because the molecules within the solution are structured in such a way that they selectively absorb photons (light particles) with the energy corresponding to green light's wavelength. This absorption excites electrons within the molecules to higher energy levels.
Here's a more detailed explanation:
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Selective Absorption: Molecules don't absorb all wavelengths of light equally. They have specific structures and electronic configurations that favor the absorption of certain wavelengths.
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Energy Levels and Transitions: Electrons within molecules can only exist at specific energy levels. To jump from a lower energy level to a higher one, an electron needs to absorb energy equal to the difference between those levels. This energy is provided by a photon of light.
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Wavelength and Energy: The energy of a photon is inversely proportional to its wavelength (E = hc/λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is wavelength). Green light has a specific wavelength that corresponds to the energy required for electrons in the molecules of the red solution to transition to a higher energy level.
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The Color We Perceive: When white light (which contains all colors) shines through a red solution, the green light is absorbed. The remaining wavelengths of light (primarily red, but also some orange and yellow) are transmitted. This transmitted light is what we perceive as the color of the solution. Therefore, a solution appears red because it absorbs green light and transmits red light.
In summary, the molecular structure of a red solution allows it to absorb photons of green light, which excites electrons within the molecule to a higher energy state. The light that is not absorbed (primarily red) is transmitted, giving the solution its characteristic color.
