Lewis electron-dot diagram is a notation that shows symbol of an atom and dots equal to the number of valence electrons.•Can be drawn for neutral atoms, ions and compounds

Neutral atom•Lewis dot diagram shows the symbol of the atom and dots equal to the number of valence electrons in the atom’s electron configuration

Sodium 2 – 8 – 1 Na ●Phosphorus 2 – 8 – 5 . . P : .

Positive ion•Lewis dot diagram for a positive ion is the same as the symbol of the positive ion.Sodium ion 2 – 8 Na+

Negative ion•Lewis electron dot diagram for a negative ion must show the symbol of the ion and 8 dots.Hydride ion 2 H :-

+2 Ca+2 is the correct symbol for a calcium ion. Ca It is also the Lewis dot diagram for a calcium 20

+2 Ca+2 is the correct symbol for a calcium ion. Ca It is also the Lewis dot diagram for a calcium 20 ion.

-1 Br Br- is the correct symbol for a bromine ion.35

.. - : Br : Lewis dot diagram for a bromide ion ..

Lewis electron dot diagram for ionic formula must show the Lewis electron dot symbols for both the positive and negative ions of the ionic compound

A correct Lewis electron dot symbol for a given ionic formula must show

CORRECT positive ion symbol of the formulaCORRECT negative ion symbol of the formulaCORRECT number of dots around the negative ion

of the formulaCORRECT number of each ion in the formula

Draw the electron dot diagram for NaClStep 1 Draw Lewis dot diagrams for atoms

. .. Na . Cl : ..

Step 2 Show electron transfer x ------- ..

Na . Cl : ..

Step 3 Show ions to complete diagrams .. -

[Na+] [: Cl :] ..

PracticeDraw the electron dot diagram for CaBr2

Draw the electron dot diagram for K2O

Lewis electron dot symbols for covalent bonding and molecules

Each pair of electrons shared between two atoms forms one (single) covalent bond.

Lewis electron dot diagrams for covalently bonded atoms must show the sharing of electrons by the nonmetal atoms.

A correct Lewis electron dot diagram for a molecular formula must show

CORRECT symbols and number of the nonmetal atoms

CORRECT number of shared electrons between the atoms

CORRECT number of valence electrons around each atom

Lewis electron dot diagrams for diatomic molecules

Step 1 Draw symbols for both atoms

H H O O N N

Step 2 Determine how many electrons MUST be put between the two atoms.H . xH .. xx

O: xx O : N .

: xxxN

Step 3 Complete each Lewis dot diagramH – H .. xx O = O :N = N: .. xx

Draw Lewis electron dot diagrams for each of the following common molecular substancesHydrogen chloride HCl

Water H2O

Ammonia NH3

Chlorine Cl2

Carbon dioxide CO2

Methane CH4

Carbon tetrachloride CCl4

PracticeDraw a Lewis electron dot diagram for a calcium atom.

Draw a Lewis electron dot diagram for a strontium ion.

Draw a Lewis electron dot diagram for a fluoride ion.

Draw a Lewis electron dot diagram for strontium bromide.

Draw a Lewis electron dot diagram for a diatomic molecule of fluorine.