Chapter 7-1 Electrons and their Energy Levels Part 2

Energy Levels The period on the periodic table represents the number of energy levels of electrons in an atom. example: Carbon is in period 2 because it has 2 energy levels

Valence Electrons Valence electrons are located only in the outer energy level. Outer energy levels are considered full or stable (inert) with eight electrons. Example: Neon has eight valence electrons. The noble gases are stable or inert. --Bohr Sketch --Lewis Structure

There is a maximum number of electrons for each energy level. Energy levels do not have to be filled to the maximum before a higher energy level begins. Example: Nickel electron configuration Ni 2 8 16 2

Valence electrons determine how an atom will react with other atoms.

Lewis Structures or Electron Dot Formulas show only valence electrons. Eight electrons (stable) is the most you can show on any atom. The noble gases have a full outer energy level and are stable or inert.