Lesson 12 · about 20 minutes

Molecules that stick together

Why oil and water stay apart, and ethanol boils far above propane.

You will learn

  • The pulls between molecules, and how they set boiling points
  • What a hydrogen bond is, and why water boils at 100 °C
  • Why oil and water separate, and what dissolves in what
  • Why ice floats, and how hydrogen bonds hold DNA's base pairs together