The Periodic Table & Electron Energy Levels
Energy Levels Electrons surround the nucleus of an atom in regions called energy levels.
Periods on the Periodic Table Each period has a new electron energy level Period 1 = 1 energy level Period 2 = 2 energy levels Period 3 = 3 energy levels
Atom models When drawing an atom, the nucleus (made of protons and neutrons) is in the center. Each energy level (filled with electrons) is a new circle around the nucleus. How many electrons are in this atom? Can you name the element? 6 electrons, means it has 6 protons It is Carbon (atomic number 6)
Valence electrons - the number of electrons in the outermost shell How many valence electrons are in Si? 4 How many valence electrons are in Ge? 4 Si Ge
Each group has the same number of. electrons in the outermost energy Each group has the same number of electrons in the outermost energy level. (valence electrons)
Valence electrons of elements on the periodic table http://www.youtube.com/watch?v=7mLPC74GHMo
Summary of the Table’s arrangement Elements are arranged by increasing atomic number Elements in the same period have the same number of electron energy levels Elements in the same group the same number of valence electrons Valence electrons are the electrons found in the outermost energy level.
Can you predict the electron arrangement just by looking at the element’s position on the table?