# 1.2 – the Octet Rule ```LECTURE 1.2 – THE OCTET RULE
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
eo Nitrogen (#7) =
o Magnesium (#12) =
o Sulfur (#16) =
o Sodium
WHAT IS THE OCTET RULE?
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 lose their valence
electrons
• All non-metals will gain the missing
ones.
WHAT ARE THE TYPES OF IONS THAT CAN FORM?
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
• If you lose electrons (detention
hrs.)  you become positive
(happy) 
CATS MAKE PEOPLE
FEEL POSITIVE
CATION  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.
MOVIE
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