Ch. 1 - A Review of General ChemistrySee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

Just because an atom satisfies its octet doesn’t mean that it is stable. We also have to consider valence electrons. Sounds familiar? Let’s look into what those are. 

Valence Electrons

Concept #1: What is a valence electron?

Every dot = 1 valence electron, and every stick = 1 valence electron. (Octet is different, see above.)

Valence Electrons and Stability

Concept #2: What is the difference between valence and octet electrons?

All of these carbons satisfy their octet, but only one of them is actually stable. The others suck. How can we tell which one will be stable?

The Periodic Table Predicts Bonding Preference

Example #1: Understanding the hydrogen isotopes. 

We can predict how many valence electrons each atom wants to have by looking up its Group Number on the periodic table.

In our example above, carbon is in Group 4A, meaning that it wants to possess 4 valence electrons, making the first structure the most stable.

Now you don't have to guess what an atom looks like in its neutral state! Simply use the periodic table to look up this information.