Photon Energy

Question 1

Answer

The energy of a color corresponds to the energy of a photon associated with a light wave, measured in electronvolts (eV).

The higher the energy, the shorter the wavelength, and vice versa.

The energy of photons in the visible spectrum typically ranges from 1.6 eV (red) to 3.3 eV (violet).

Question 2

Answer

Converting an energy value in eV to a visible color relies on the relationship between energy, frequency, and wavelength.

Here are approximate energy ranges associated with visible colors:

— 1.6–2.1 eV (Red)

— 2.1–2.3 eV (Orange)

— 2.3–2.4 eV (Yellow)

— 2.4–2.8 eV (Green)

— 2.8–3.1 eV (Blue/Cyan)

— 3.1–3.3 eV (Violet/Blue)

These values are average estimates and may slightly vary between sources.

Question 3

Answer

The energy (E) of a photon is proportional to the frequency (f) of the light wave. It is given by the formula (in Joules):

$$ E = h \times f $$

where:

— $ E $ is the energy in Joules (J)

— $ h $ is Planck's constant (approximately $ 6.626 \times 10^{-34} J \cdot s $)

— $ f $ is the frequency in Hertz (Hz)

Knowing that the conversion from Joules to eV is done using the relationship $ 1 eV = 1.6 \times 10^{-19} J $

The formula (in electron-Volt) simplifies: $ E = f \times 4.1357 \times 10^{-15} eV $

Example: Red has a wavelength of 650 nm, a frequency of 460 THz, or a photon energy $ E = 460 \times 4.1357 \times 10^{-15} \approx 1.9 eV $

Question 4

Answer

Some colors do not come from a single light wave (they are not monochromatic) but from a mixture of several wavelengths.

Example: White, gray, black: depend on the overall quantity of light, not on a specific energy.

Example: Pink, magenta: come from a combination of red and blue.

Example: Brown: a dark hue derived from a low intensity of red/orange light.

These colors therefore do not have a single photon energy but are the result of complex perceptual compositions.

Energy to Color Converter