Answer:
It is not a property of light. It is your eyes and brain.
Specifically, the three kinds of cone cells in our eye that are sensitive to different ranges of the electromagnetic spectrum. The fact that there are three means that color is three dimensional, and is the reason the pure colors form a circle even though the spectrum of wavelengths is linear.
Visible light is part of the electromagnetic spectrum; light waves of different frequencies and wavelengths are distinguished as colors by the human eye. A prism can separate the colors of white light (dispersion) because different frequencies of light have different refractive indices for a given material.
This group is called “noble gases” because they do not react with other elements. This is because they have a full valence shell.
Answer:
i)20369 photons
ii) 40 ps
Explanation:
Momentum of one Sodium atom:

In other to stop it, it must absorb the same momentum in photons:

Now, for the minimun time, we use the speed of light and the wavelength. For the n photons:

Here’s my work to your question. I used Newton’s Second Law and a kinematics equation to arrive at the answer.