Everyday Examples of Matter: Solids, Liquids, and Gases Around Us

📚 Quick Study Guide

• 🧊 Solids: Have a definite shape and volume. Examples: Rocks, wood, ice. The molecules are tightly packed together.
• 💧 Liquids: Have a definite volume but take the shape of their container. Examples: Water, milk, oil. The molecules are less tightly packed than in solids.
• 💨 Gases: Have no definite shape or volume and can be compressed. Examples: Air, oxygen, helium. The molecules are widely dispersed and move freely.
• 🌡️ Phase Changes: Matter can change between solid, liquid, and gas through processes like melting (solid to liquid), boiling (liquid to gas), freezing (liquid to solid), condensation (gas to liquid), and sublimation (solid to gas).
• ⚛️ Molecular Motion: The kinetic energy of molecules increases with temperature. This increased motion is what causes phase changes.

🧪 Practice Quiz

1. Which of the following is an example of a solid?

   1. Air
   2. Water
   3. Ice
   4. Steam

2. Which of the following is an example of a liquid?

   1. A rock
   2. Orange juice
   3. Oxygen
   4. A tree

3. Which of the following is an example of a gas?

   1. Table salt
   2. Cooking oil
   3. Nitrogen
   4. A chair

4. What process describes a liquid changing to a gas?

   1. Melting
   2. Freezing
   3. Boiling
   4. Sublimation

5. What state of matter has a definite volume but takes the shape of its container?

   1. Solid
   2. Liquid
   3. Gas
   4. Plasma

6. Which of the following phase changes involves a solid changing directly into a gas?

   1. Melting
   2. Freezing
   3. Boiling
   4. Sublimation

7. In which state of matter are the molecules most tightly packed?

   1. Solid
   2. Liquid
   3. Gas
   4. Plasma