Question

Which color of light comes from a greater energy transition, red or blue?

Short answer

Blue light has greater energy because it has a higher frequency than red light.

Step-by-step solution

Understand Energy of Photons

Energy of a photon is determined by its frequency. Recall the equation for photon energy, \( E = h \cdot f \), where \( E \) is energy, \( h \) is Planck's constant, and \( f \) is frequency. A greater frequency implies more energy.

Relate Color to Frequency

Different colors of light have different frequencies. Blue light has a higher frequency compared to red light in the visible spectrum.

Compare Energies

Since energy is directly proportional to frequency, blue light with higher frequency will have greater energy compared to red light, which has a lower frequency.

Key concepts

Photon Frequency

The frequency of a photon is a core concept to grasp when studying the energy of light. Frequency refers to how many waves pass a point in one second. It is measured in hertz (Hz).
For photons, which are particles of light, frequency determines their energy. The relationship is found in the equation: \[E = h \cdot f\]
Here, \( E \) stands for energy, \( h \) is Planck's constant, and \( f \) is the frequency. This equation tells us that a photon with a higher frequency has more energy.
Understanding this concept helps explain why different colors of light have different energies.

Visible Spectrum

The visible spectrum represents the range of light that can be seen by the human eye. It includes a variety of colors, each corresponding to a different wavelength and frequency.
In the visible spectrum:

• Red light has the longest wavelength and lowest frequency.
• Blue and violet light have shorter wavelengths and higher frequencies.

Each color in the visible spectrum has unique properties due to its specific frequency and wavelength. These differences explain why certain colors appear as they do and how they behave in various applications.

Planck's Constant

Planck's constant is a fundamental value used to describe the energy of photons. It is denoted by the symbol \( h \) and is about \( 6.626 \times 10^{-34} \) joule seconds.
Named after Max Planck, who is considered the father of quantum theory, this constant bridges the energy and frequency of a photon. Without it, calculating the energy of light would be impossible.
Planck's constant highlights the small scale of the energy differences between different frequencies and helps in understanding phenomena in quantum mechanics.

Color and Frequency

Color and frequency are deeply intertwined concepts in the study of light. Each color of light has its unique frequency, which affects its energy level. For instance:

• Red light has a lower frequency and hence less energy.
• Blue light has a higher frequency and thus more energy.

These distinctions in energy and frequency explain why blue light is more energetic than red light.
In practical terms, understanding the relationship between color and frequency allows us to comprehend various phenomena, from why the sky is blue to how light interacts with different materials.