TIGER

21.1. Formation of the Elements, 996
21.2. Terrestrial Elements, 998
21.3. Some Main Group Elements Extracted by Physical Methods: Nitrogen, Oxygen, and Sulfur, 1002
21.4. Some Main Group Elements Extracted by Electrolysis: Sodium, Chlorine, Magnesium, and Aluminum, 1003
21.5. Some Main Group Elements Extracted by Chemical Oxidation-Reduction: Phosphorus, Bromine, and Iodine, 1009
21.6. A Periodic Perspective: The Main Group Elements, 1012