1. Halogen – Fluorine (F)Halogens are in Group 17. Fluorine is the most reactive halogen and nonmetal.2. Chalcogen – Oxygen (O)Chalcogens are in Group 16. Oxygen is essential for respiration and forms oxides with most elements.3. Alkali Metal – Sodium (Na)Alkali metals are in Group 1. Sodium is soft, reactive, and forms +1 ions.4. Boron Group – Boron (B)Boron is in Group 13, known as the boron group. It’s a metalloid and essential in plant nutrition.5. Lanthanide Series – Cerium (Ce)Lanthanides are elements with atomic numbers 57–71. Cerium is used in catalytic converters and glass polishing.6. Alkaline Earth Metal – Calcium (Ca)Alkaline earth metals are in Group 2. Calcium is vital for bones and teeth.7. Noble Gas – Neon (Ne)Noble gases are in Group 18. Neon is inert and used in glowing signs.8. Transition Metal – Iron (Fe)Found in the d-block, transition metals like iron are good conductors and can form variable oxidation states.