Answer:
an electron is a wavelength of energy that orbits a nucleus at the speed of light in an orbital where only one other electron can exist with an opposite spin, the electons in the orbitals in the outermost energy levels are valence electrons.
ex: C= 1s^2 2s^2 2p^2 (the second energy level ((the outermost in this example)) contains a total of 4 electrons or its valence electrons)