Chapter 10 · Chemical Bonding
10.1Bonding Models and AIDS Drugs
8 min · two checks
Predict
Why does the shape of a molecule decide whether a drug works?
The idea
- Explain why bonding models are practical, not decorative.
- Name the two main bond types this chapter separates.
A chemical formula says which atoms are present. It does not say how they are connected or what shape that connection creates. Drug design, enzyme action, and the difference between two molecules with the same formula all depend on shape and on where the electrons sit. Bonding models exist to predict those things from a short set of rules.
This chapter uses the Lewis model. Ionic bonding is electron transfer that produces attracted ions. Covalent bonding is electron sharing that produces molecules. Most real bonds are somewhere between those extremes, and electronegativity is how you locate them on that line. The model is simple on purpose. It fails for some molecules and still organizes most of the ones a first course meets.
Keep these
- Shape and electron distribution decide how molecules interact.
- Ionic bonding transfers electrons. Covalent bonding shares them.
- A model is a set of predictions, not a photograph of the electrons.