Inter vs. Intramolecular bonds

INTRA -- within (inside a particle <- think covalent bonds)

INTER -- between (felt between separate particles)

Notice, the H2O has intramolecular bonds and the Mg does not. The Mg is mixed with water but it is not bonded with intramolecular bonds.

Evaporation Rates

Ionic vs. Covalent

Covalent Prefixes

 MEMORIZE these prefixes.

Lewis Dot Covalent - Methods

Method #1:


Method #2:

1. Count the total number of electrons.
2. Draw a structure with single bonds.
3. Starting on the outside start adding dots in pairs so that each element is touching the appropriate number of electrons (H's = 2, all other elements = 8).
   COUNT AS YOU GO - remembering your goal from #1
4. When you only have 4 electrons left - stop and look to see if you're going to run out. If you're going to run out start adding a double or a triple bonds with your final electrons.
5. DOUBLE CHECK -- count to make sure everything is touching the appropriate number. Count to make sure you haven't gone over or below your total number from #1.
6. Double check -- if you have multiple places where a double or triple bond could have gone - double check that you picked the right spot. What's the right spot?? IF elements have a choice they prefer to follow the "Step 5" rule. [ # of valence electrons + bonds = 8]. Sometimes atoms don't get a choice, but when they do they prefer a particular arrangement. Ex: Carbon Dioxide prefers a O=C=O instead of a single and triple bond.

Ion Charges

Naming Ionics

 

Lewis Dot Ionic

Use families on the periodic table to identify how many valance electrons (represented by dots) each element has. 

Metals will LOSE electrons

and

Nonmetals will GAIN electrons

Metals lose all their valance electrons (they have other electrons in layers beneath), which nonmetals gain until they have 8 valance electrons. They ionically bond in whatever ratio is necessary for all the metals to lose electrons and all nonmetals to gain until they get to 8.

Gas Stations

Law & Theory

Scientific Laws: Patterns that we notice in nature. (WHAT is happening)

Scientific Theories: Explanations or models for what we see in nature. (WHY something is happening)

KMT or Kinetic Molecular Theory is what we use to help explain why. For example we might talk about pressure changes by talking about collisions. This isn't just a statement of the pattern, this is our explanation of what we believe is happening at the microscopic level.

Gas Law Relationships