Here's why:

* Electromagnetic Spectrum: Light is a form of electromagnetic radiation. The electromagnetic spectrum arranges different types of light based on their wavelengths and frequencies.

* Wavelength and Energy: The energy of light is inversely proportional to its wavelength. This means that shorter wavelengths have higher energy, and longer wavelengths have lower energy.

* Green vs. Yellow: Green light has a shorter wavelength than yellow light.

* Green light wavelength: Approximately 520-570 nanometers

* Yellow light wavelength: Approximately 570-590 nanometers

Therefore, since green light has a shorter wavelength than yellow light, it has more energy.