CA Standards • Students can determine the number of valence electrons for an element, draw a Lewis dot notation for an element and explain how the Octet rule leads to the formation of ions.
I. VALENCE SHORTCUT! • All elements in the same group (1A, 2A, etc.) have the same number of valence electrons. • Lewis Dot Notation shows only Valence e- • Nitrogen (#7) = • Magnesium (#12) = • Sulfur (#16) = • Sodium
II. The Octet Rule • Atoms like to have a full outer valence shell Stable atom. • gain or lose electrons to have an outer orbit with 8 electrons (or 2 if it is the first energy level). • Gain/lose based on what is easiest.
III. Octet SHORTCUT • All metals will losetheir valence electrons • All non-metals will gain the missing ones.
IV. Ions • When atoms gain/lose electrons, they gain a charge. • Ion– A charged atom due to unequal number of protons and electrons • Cation– A positively charged ion • Anion– A negatively charged ion
E- = detention hrs. • If you gain electrons (detention hrs.) you become negative (sad) • If you lose electrons (detention hrs.) you become positive (happy)
CATION POSITIVE Cats make people feel positive ANION NEGATIVE
Class Example • Draw dot notation for Be. Determine the ion that forms for fluorine after the Octet Rule has been satisfied.
Table Talk • Draw the dot notation for Chlorine. Determine the ion that forms for nitrogen after the Octet Rule has been satisfied.
Stop and Jot • Draw the dot notation for Sulfur. Determine the ion that forms for oxygen after the Octet Rule has been satisfied.
Ion Shortcut! • All elements in the same group, form ions with the same charge.