Describe how atomic emission spectrums came about, and what they say about atoms/electrons.

Atomic emission spectrum came out by a series of colored lines

Explanation:

When electricity is passing through an element or when it is viewing through a prism, a unique spectra of light emitted by an element is called atomic emission spectra. They are acting as an element of finger print because they are unique.  When we are seeing a set of colored lines or a black background  , it is an emission spectrum. If we are watching black lines on a colored background it is absorption spectrum.  In electromagnetic spectrum the visible portion are the colors.

In nucleus electrons can exist in some areas are known as shells. Shell corresponds an energy level that is designed by a quantum number n. The lowest energy level electrons are close to the nucleus.

An atom is shone by light, its electrons absorbs photons and it gain energy, and jump to higher level.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.