IGCSE Study Buddy: States of Matter

Introduction

• Matter: Everything with mass that occupies space, made up of tiny particles.
• States of Matter: Solids, liquids, and gases.

Basic Properties of States of Matter

1. Solids
   • Fixed volume and shape.
   • Particles are tightly packed.
2. Liquids
   • Fixed volume but take the shape of their container.
   • Particles can move around slightly.
3. Gases
   • No fixed volume, take the shape of their container.
   • Particles move freely.

Structure of Solids, Liquids, and Gases

• Particle Separation

  • Solids: Very close together.
  • Liquids: Slightly separated.
  • Gases: Far apart.

• Arrangement

  • Solids: Orderly pattern.
  • Liquids: Disorganized.
  • Gases: Highly disordered.

• Motion

  • Solids: Limited to vibrations.
  • Liquids: Slide past each other.
  • Gases: Move rapidly and freely.

Changes of State

1. Melting

   • Solid to liquid.
   • Particles gain kinetic energy, vibrate until melting point.
   • Example: Ice melts at 0°C.

2. Boiling

   • Liquid to gas at boiling point.
   • Particles gain kinetic energy.
   • Example: Water boils at 100°C.

3. Evaporation vs. Boiling

   • Boiling: At boiling point, rapid change.
   • Evaporation: Slower, occurs at various temperatures.
   • Example: Puddles dry as liquid evaporates.

4. Condensing

   • Gas to liquid.
   • Particles lose kinetic energy, slow down.
   • Example: Steam condenses into water droplets.

5. Freezing

   • Liquid to solid.
   • Particles arrange into a solid structure.
   • Example: Water freezes at 0°C.

Heating and Cooling Curves

• Heating Curve

  • Shows state changes as temperature increases.
  • Solid to liquid (melting), liquid to gas (boiling).

• Cooling Curve

  • Temperature decreases, gas to liquid to solid.
  • Horizontal sections indicate state changes.

Effect of Temperature and Pressure on Gases

• Temperature Increase: Particles move faster, gas expands (increased volume).
• Pressure Increase: Particles are compressed, gas volume decreases.

Diffusion

• Movement from high to low concentration.
• Kinetic Particle Theory: Particles in constant motion and collision.
• Relative Molecular Mass: Lighter gases diffuse faster (e.g., Helium vs. Oxygen).

Conclusion

• Importance of understanding states of matter and changes.
• Encouragement to subscribe for more educational content.