Khan Academy: Introduction to Gravity

Video provides a basic introduction to the phenomenon of light, the electromagnetic radiation spectrum, wave and particle-like behavior, and how to calculate the wavelength or frequency of a light wave. [9:36]

Introduction to how groups of organisms evolve and how natural selection can lead to evolution. [17:39]

An introduction to entropy and its relationships to various states for a system. [7:27]

Introduction to the reaction quotient Qc, and comparing the reaction quotient with the equilibrium constant to predict how concentrations will change. [7:36]

Introduction to redox in cellular respiration. Provides an overview of how cells break down fuels and looks at some of the electron transfer reactions that are key to this process.

An introduction to buffer systems, which regulate pH in blood. [6:20]

This video compares a voltaic cell to an electrolytic cell. [6:51]

Video offers the big picture view of chemistry and takes a look at how it relates to math and other sciences. [7:45]

A video introducing the two different processes of metabolism: catabolism and anabolism. Video gives lots of example to explain that catabolism is a process of breaking down and anabolism rebuilds matter. [10:06]

A video lecture explaining what happens in an addition reaction to an alkene. [11:21]