Question and Answers on States of Matter.

1. What is matter?
   Answer: Matter is anything that has mass and takes up space.

2. What are the three main states of matter?
   Answer: Solid, liquid, and gas.

3. What are the properties of solids?
   Answer: Solids have a definite shape and volume.

4. What are the properties of liquids?
   Answer: Liquids have a definite volume but take the shape of their container.

5. What are the properties of gases?
   Answer: Gases have no fixed shape or volume and spread to fill their container.

6. What is the fourth state of matter?
   Answer: Plasma (found in stars and lightning).

7. What happens when matter is heated?
   Answer: It can change from solid to liquid (melting) or liquid to gas (evaporation).

8. What happens when matter is cooled?
   Answer: It can change from gas to liquid (condensation) or liquid to solid (freezing).

9. What is the smallest unit of matter?
   Answer: Atom.

10. What are molecules?
    Answer: Molecules are made up of two or more atoms bonded together.

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11. What is melting?
    Answer: The process of changing a solid into a liquid.

12. What is freezing?
    Answer: The process of changing a liquid into a solid.

13. What is evaporation?
    Answer: The process of changing a liquid into a gas.

14. What is condensation?
    Answer: The process of changing a gas into a liquid.

15. What is sublimation?
    Answer: When a solid changes directly into a gas without becoming a liquid (e.g., dry ice).

16. What is deposition?
    Answer: When a gas changes directly into a solid (e.g., frost forming on windows).

17. At what temperature does water freeze?
    Answer: 0°C or 32°F.

18. At what temperature does water boil?
    Answer: 100°C or 212°F.

19. What is boiling?
    Answer: A rapid change from liquid to gas at a specific temperature.

20. Why does ice float on water?
    Answer: Because ice is less dense than liquid water.

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21. What is mass?
    Answer: The amount of matter in an object.

22. What is volume?
    Answer: The amount of space an object takes up.

23. What is density?
    Answer: The amount of mass in a given volume of a substance.

24. How can you measure the volume of a liquid?
    Answer: Using a measuring cup or graduated cylinder.

25. How can you measure the mass of an object?
    Answer: Using a balance or scale.

26. Why does a balloon filled with air take up space?
    Answer: Because gases have volume and fill their container.

27. Can gases be compressed?
    Answer: Yes, gases can be compressed to fit into a smaller space.

28. Why do liquids take the shape of their container?
    Answer: Because the molecules in a liquid move freely.

29. What happens to the molecules in a solid?
    Answer: They are packed tightly and vibrate in place.

30. What happens to the molecules in a gas?
    Answer: They move freely and spread out to fill any space.

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31. What is a mixture?
    Answer: A combination of two or more substances that can be separated.

32. What is a solution?
    Answer: A mixture where substances dissolve completely (e.g., salt in water).

33. What is solubility?
    Answer: The ability of a substance to dissolve in a liquid.

34. What is an example of an insoluble substance?
    Answer: Sand does not dissolve in water.

35. How can you separate a mixture of sand and iron filings?
    Answer: Using a magnet to attract the iron filings.

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36. Why does a metal spoon feel colder than a plastic spoon?
    Answer: Because metal conducts heat better than plastic.

37. Why does a puddle disappear on a hot day?
    Answer: The water evaporates into the air.

38. Why do your glasses fog up when you come inside from the cold?
    Answer: Warm air condenses on the cold surface of the glasses.

39. Why does a solid expand when heated?
    Answer: The molecules move faster and spread apart.

40. Why do ice cubes shrink in the freezer over time?
    Answer: They slowly undergo sublimation, turning into gas.