1. Ions with Lewis Dot structures

2. Abbreviating Lewis Dot Structures
It can sometime be tedious writing out all the dots, and they can also be difficult to see.
So it is very common to use a dash to represent a pair of electrons.
So… .. .. :O
:Cl: H .. ..
H-O-Cl
becomes

3. If it’s a double bond O=C=O
single bond is a single dash, double bond is a double dash.
So CO2
Make sure bonds connect the elements, and unpaired electrons don’t connect to another element
O=C=O

4. Lewis dot structures with ions

5. First things first! .. .. Na. .Cl: Na [ ] :Cl: .. ..
Determine whether the bond will be ionic or covalent!
A nonmetal and a metal is ionic if they are both nonmetals it is covalent, hydrogen is not a metal.
To draw an ionic bond remove the electron(s) from the cation and add them to the anion. Show the charges on each ion. .. .. + -
Na.
.Cl: Na
[ ]
:Cl: .. ..

6. It has an extra electron
For Polyatomic Ions…
The polyatomic ion is a covalently bonded structure with an ionic bond to another substance.
NH4F H . F
H-N-H . H
That goes to Fluoride
It has an extra electron

7. It has an extra electron
For Polyatomic Ions…
The polyatomic ion is a covalently bonded structure with an ionic bond to another substance.
NH4F - + H F
H-N-H H
That goes to Fluoride
It has an extra electron

8. Polyatomic Ions we need to know

9. [ ] Ammonium + H H H-N-H H-N-H . H H What happens
What it looks like when done +
[ ] H H
H-N-H
H-N-H . H H

10. [ ] Hypochlorite - - - O-Cl - - - - O-Cl - - - - . - What happens
What it looks like when done . - -
[ ] -
- -
O-Cl - -
- -
O-Cl -
- -

11. [ ] Hydroxide - O-H - - O-H - - . - What happens
What it looks like when done .
[ ] - - -
O-H - -
O-H -

12. [ ] Nitrite - - - - - - O-N=O - - - O-N=O - - . - What happens
What it looks like when done . - - -
[ ] -
O-N=O -
O-N=O

13. [ ] Acetate - - - - O= - H O= H - - O-C-C-H - - - - - - O-C-C-H - H H
What happens
What it looks like when done - - - - O= - H . O= H
[ ] - -
O-C-C-H
- - -
- - -
O-C-C-H - H H

14. Homework
Redo the Lewis Dot worksheet with dashes