How did the world find out about the unsung heroes**?

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole

Stage in which a typical star has completely stopped fusion

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?