Ozone, made of three bonded oxygen atoms, is found 15-30 km above Earth, has a strong smell, is blue, and blocks sunlight from hitting the surface of Earth. The 22nd lesson in a series of 36 specifically focuses on the important elements...

Although their name makes them sound dangerous or toxic, carboxylic acids are found throughout nature in things such as citric acid, vinegar, and even in your DNA. Through detailed readings, discussions, and answering questions...