Group 2 Always forms +2 ions – Group 17 Always forms -1 ions – Oxygen/Sulfur Forms -2 ion; Nitrogen forms -3 ion – Non-Metals Use the top charge/oxidation state on your periodic table – Transition Metals Can form ions with multiple charges. Can only determine – charge in a compound **When an atom gains or loses electrons, the resulting electron configuration is typically the same configuration as a neutral noble gas, the stable Group 18 elements** Dot Structures Atoms and Ions – Draw the symbol for the atom Count how many valence electrons the atom has Begin adding electrons (represented by dots) to the top, right, bottom and left side of the symbol After you have added four dots or electrons, begin to pair them Examples: Energetics of Bonding! Breaking a bond always takes energy endothermic – Making a bond always released energy exothermic – Systems tends to move towards more stable, lower energy states More on this when we get to kinetics and thermodynamics! Ionic Bonding Ionic bonding involves a transfer of electrons
Group 2 – Always forms +2 ions Group 17 – Always forms -1 ions Oxygen/Sulfur – Forms -2 ion; Nitrogen forms -3 ion Non-Metals – Use the top charge/oxidation state on your periodic table Transition Metals – Can form ions with multiple charges. Can only determine charge in a compound **When an atom gains or loses electrons, the resulting electron configuration is typically the same configuration as a neutral noble gas, the stable Group 18 elements** Dot Structures – Atoms and Ions Draw the symbol for the atom Count how many valence electrons the atom has Begin adding electrons (represented by dots) to the top, right, bottom and left side of the symbol After you have added four dots or electrons, begin to pair them Examples: Energetics of Bonding! Breaking a bond always takes energy – endothermic Making a bond always released energy – exothermic Systems tends to move towards more stable, lower energy states More on this when we get to kinetics and thermodynamics! Ionic Bonding Ionic bonding involves a transfer of electrons
unit-3-exam-review-sheet.docx