Light with a wavelength of 525nm is green. Calculate the energy in joules for a green light photon
The correct answer and explanation is:
Correct Answer:
The energy EE of a photon of green light with a wavelength of 525 nm is approximately 3.78 × 10⁻¹⁹ joules.
Explanation:
To calculate the energy of a photon, the equation used is: E=hcλE = \frac{hc}{\lambda}
Where:
- EE is the energy of the photon in joules (J)
- hh is Planck’s constant, 6.626×10−34 J\cdotps6.626 \times 10^{-34} \, \text{J·s}
- cc is the speed of light in a vacuum, 3.00×108 m/s3.00 \times 10^8 \, \text{m/s}
- λ\lambda is the wavelength in meters
The given wavelength is 525 nm. To use the equation, the wavelength must be converted to meters: 525 nm=525×10−9 m525 \, \text{nm} = 525 \times 10^{-9} \, \text{m}
Now substitute the values into the energy equation: E=(6.626×10−34)(3.00×108)525×10−9E = \frac{(6.626 \times 10^{-34})(3.00 \times 10^8)}{525 \times 10^{-9}} E=1.9878×10−255.25×10−7=3.787×10−19 JE = \frac{1.9878 \times 10^{-25}}{5.25 \times 10^{-7}} = 3.787 \times 10^{-19} \, \text{J}
So the energy of one photon of green light with a wavelength of 525 nm is approximately 3.78 × 10⁻¹⁹ joules.
This value reflects the fact that shorter wavelengths correspond to higher energy photons. Green light lies in the middle of the visible spectrum, with energy values higher than red light and lower than violet light. Understanding photon energy is essential in fields like quantum physics, photochemistry, and electronics, where light-matter interactions play a major role.