Arrange the colors of visible light, green, red, and blue, in order of increasing wavelength.
blue < green < red
shortest wavelength red < green < blue longest wavelength
green < blue < red

The increasing wavelength of colors:

Red > Green > Blue

Explanation:

Wavelength: This is the property of wave which includes the distance between two consecutive crests or trough. This is denoted by the Greek letter Lambda and it is found by dividing the velocity of the wave with its frequency.

Wavelength of colours are

Violet: 400 - 420 nm

Indigo: 420 - 440 nm

Blue: 440 - 490 nm

Green: 490 - 570 nm

Yellow: 570 - 585 nm

Orange: 585 - 620 nm

Red: 620 - 780 nm

the answer for sodium is 0.186

the answer for rubidium is 0.251

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.