It should be radio waves. If you need anymore help look up the wavelength chart online.
For 2 it’s 2ft 10in
For 5 it’s 3ft 6in
You: put how tall you are
Adult: you can either measure an adult or use this 5 ft 10in
The main function is to help them see with all their eyes.
When sodium amide i.e.
reacts with water i.e.
results in the formation of sodium hydroxide i.e.
and ammonia
.
The chemical reaction is given by:

Now, when ammonia i.e.
reacts with water results in the formation of ammonium hydroxide i.e. 
The chemical reaction is given by:

Thus, the products of the above reactions are ammonia and ammonium hydroxide (without sodium ion).
The structures of the products are shown in figure (1): ammonium hydroxide and figure (2) ammonia.
Rainbows go in the order of ROYGBIV, which is an acronym for red, orange, yellow, green, blue, indigo, violet.
So, it would start off with red.
If you want to know why it starts off the rainbow, its because red has the longest wavelength, compared to the rest of the colors. (sorry I'm rambling, I got excited)
Hope this helps.