1. Chapter 19
Chemical Bonds

2. Section 1
What is Bonding

3. when atoms combine and form new substances with different
Bonding
when atoms combine and form new substances with different
properties.
Example - SALT(clear,edible solid)
from: SODIUM(soft,grey metal)
CHLORINE(green gas)

4. Formulas A shorthand way of showing which
elements and how much are in a compound.
Example - SUGAR: C12H22O11
C,H,O are elements
12,22,11 are subscripts(#of atoms)

5. Why do atoms bond ?
Because their outside level is not full (stable)
Can become full by GIVING, TAKING or SHARING e-
Example - Dot Diagrams can help see this: . : O: .

6. Section 2
Types of bonds

7. Bonding Ionic Metal/nonmetal Give/Take e- Strongest Bond Forms hard
crystals, high melting points
Charged atoms - called IONS
Covalent
nonmetal/nonmetal
Share e-
Weaker bond
Forms liquids, and gases, low M.P. Solids
Called a MOLECULE
Can share 1,2 or 3 pairs of e-

8. Writing Formulas & Naming Compounds
Section 3
Writing Formulas
&
Naming Compounds

9. 3 simple steps to naming binary ionic (2 part) compounds:
Naming Compounds
3 simple steps to naming binary ionic (2 part) compounds:
Write the positive ion (metal)
Write the negative ion (nonmetal)
Drop the ending of the negative
and add IDE.

10. Special Situations Covalent compunds need prefixes:
mono, di, tri, tetra, penta
2.Polyatomic ions: use their name(see sheet)
3.Transition Metals: use Roman numerals to show charge

11. Important Definition:
Writing Formulas
Important Definition:
OXIDATION NUMBER - Number that shows how many e- an atom has gained (-) or lost (+).
Example: Al3+ - Aluminium lost 3 e-
S2- - Sulfur gained 2 e-

12. 3 simple steps to writing formulas:
Write the symbol of the positive oxidation element.
Write the symbol of the negative oxidation element or polyatomic ion.
Add subscripts to each part so that their sum =0.