Pure Substances:
1. Water (H₂O): Found in rivers, lakes, and rain.
2. Gold (Au): Used in jewelry, electronics, and dentistry.
3. Salt (NaCl): Used for seasoning food and preserving it.
4. Sugar (C₁₂H₂₂O₁₁): Sweetener found in various forms like granulated, brown, and powdered sugar.
5. Diamond (C): A precious gem known for its hardness and brilliance.
6. Oxygen (O₂): The gas we breathe.
7. Helium (He): A lighter-than-air gas used in balloons and scientific research.
8. Iron (Fe): A strong metal used in construction and manufacturing.
9. Copper (Cu): A reddish-brown metal used in wiring, plumbing, and coins.
10. Mercury (Hg): A heavy, liquid metal used in thermometers and barometers.
Impure Substances:
11. Seawater: A mixture of water, salts, and other dissolved substances.
12. Milk: A mixture of water, fats, proteins, and carbohydrates.
13. Air: A mixture of gases including nitrogen, oxygen, carbon dioxide, and others.
14. Soil: A mixture of rock particles, organic matter, water, and air.
15. Blood: A mixture of blood cells, plasma, and other components.
16. Coffee: A mixture of water and coffee grounds.
17. Tea: A mixture of water and tea leaves.
18. Fruit juice: A mixture of water, sugars, and fruit pulp.
19. Sand: A mixture of various rock particles.
20. Concrete: A mixture of cement, sand, gravel, and water.
