1. We know air is there because we can feel, hear, and see its effects even if we can’t see it.

2. Air doesn’t float into space because Earth’s gravity holds it close to the surface.

3. If wind never stopped, it could cause constant storms, damage, and make it hard for plants, animals, and people to live peacefully.

4. We can go up to about 8,000 meters before breathing gets hard, and above 20,000 meters there's almost no air to breathe.

5. Air feels cooler when it moves because it carries heat away from our skin faster than still air.

6. Tap water comes from rivers, lakes, or underground and is cleaned before reaching your home.

7. Ocean water doesn’t spill off Earth because gravity pulls it into a round shape, like a ball.

8. Water can be a solid, liquid, or gas depending on temperature—ice when cold, liquid when normal, and steam when hot.

9. If all the ice melted, sea levels would rise and flood many coastal places on Earth.

10. Sea water is salty from minerals in rocks, but rainwater isn’t because it comes from evaporated, cleaned water.