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Matter: States and Changes

🔬 Basic Science 📋 JSS2 📅 First Term ⏱ ~20 min 📝 5 quiz questions
📖 Content 📝 Quiz (5)

What is Matter?

Matter is anything that has mass and occupies space. All physical objects are made of matter.

States of Matter

StateShapeVolumeExamples
SolidFixedFixedWood, rock, ice
LiquidTakes container shapeFixedWater, oil, mercury
GasNo fixed shapeNo fixed volumeAir, steam, oxygen

Changes of State

  • Melting: solid → liquid (ice melts into water at 0°C)
  • Freezing: liquid → solid (water freezes at 0°C)
  • Evaporation/Boiling: liquid → gas (water boils at 100°C)
  • Condensation: gas → liquid (steam becomes water droplets)
  • Sublimation: solid → gas directly (camphor, dry ice)

Pure Substances and Mixtures

  • Pure substance: one type of matter only — water, gold, salt
  • Mixture: two or more substances combined — soil, air, jollof rice
  • Solution: a mixture where one substance dissolves in another — salt in water
💡 In everyday life, most things we see are mixtures. Even air is a mixture of nitrogen (78%), oxygen (21%), and other gases.

📝 Quiz — Test Your Understanding

Answer all 5 questions, then click Submit to see your result.

Question 1 of 5
Which state of matter has a fixed shape and fixed volume?
Solids have particles packed tightly in a fixed arrangement, giving them both fixed shape and fixed volume.
Question 2 of 5
What change of state occurs when liquid water becomes steam?
Liquid → gas is called evaporation (at surface) or boiling (throughout the liquid). Both are the same change of state.
Question 3 of 5
At what temperature does pure water boil at sea level?
Pure water boils at 100°C (212°F) at standard atmospheric pressure (sea level).
Question 4 of 5
Which of these is a mixture?
Air is a mixture of gases — mainly nitrogen (78%) and oxygen (21%), with traces of other gases.
Question 5 of 5
Camphor changing directly from solid to vapour is an example of:
Sublimation is the change from solid directly to gas without passing through the liquid state.
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