Across
- 4. A measure of how hot or cold something is. It tells you the average amount of energy the particles in a substance have.
- 9. The tiny, basic building block of all matter. It's the smallest part of an element that still has the properties of that element (like hydrogen or oxygen).
- 10. Any water that falls from the clouds to the Earth's surface, like rain, snow, sleet, or hail.
Down
- 1. A group of two or more atoms stuck together
- 2. How fast something is moving. It's calculated by the distance traveled divided by the time it took.
- 3. A push or a pull on an object. A force is needed to start, stop, or change the direction of something moving.
- 5. The thick blanket of gases (like air) that surrounds the Earth. Gravity keeps this layer from floating away into space.
- 6. The average weather conditions in an area over a very long time, usually 30 years or more. It describes what the weather is usually like there (e.g., a tropical climate is usually hot and rainy).
- 7. A force that resists (or works against) motion when two objects or surfaces rub against each other. It's why a rolling ball eventually stops.
- 8. The natural force that pulls everything toward everything else. It's what keeps your feet on the ground and makes apples fall from trees.