Final answer:
A 700 nm photon has less energy than a 400 nm photon.
Step-by-step explanation:
The energy of a photon is directly proportional to its frequency or inversely proportional to its wavelength. Higher frequency photons have more energy, while lower frequency photons have less energy.
Since the wavelength of a 700 nm photon is longer than that of a 400 nm photon, the 700 nm photon has less energy than the 400 nm photon.
Using the energy-frequency relationship E = hf, where E represents energy, h is Planck's constant, and f is frequency, the energy of a photon can be calculated.