In this lesson, Mrs. Ted discusses the topic of rusting, focusing on the chemical process and conditions necessary for it to occur, such as the presence of oxygen, water, and electrolytes. She outlines an experiment using iron nails and various environments, including normal water, salt water, and oil, to demonstrate how these conditions affect rusting. The lesson emphasizes that while iron rusts quickly when exposed to these elements, other metals like gold undergo corrosion much more slowly due to their lower reactivity.