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Worksheet StudioPractice pack · Ages 7-9
Solids, liquids & gases
Take your time. Show your thinking.
1. Why does the smell of baking bread spread across a quiet room even without wind: diffusion (random particle motion from high to low concentration), or gravity?
Solid → Liquid → Gas · Particle Arrangement
2. Which metallic element is unusual because it is a liquid at standard room temperature (20 °C): mercury or iron?
Solid → Liquid → Gas · Particle Arrangement
3. Which state of matter has a fixed volume but flows to take the shape of the bottom of its container: liquid or solid?
Solid → Liquid → Gas · Particle Arrangement
4. What is the change of state from a liquid to a solid when cooled: freezing (solidification) or evaporation?
Solid → Liquid → Gas · Particle Arrangement
5. In which state of matter do particles have the highest average kinetic energy at a given pressure: gas (steam) or solid (ice)?
Solid → Liquid → Gas · Particle Arrangement
6. Why does a wet shirt dry faster on a windy day than on a still day: wind sweeps away humid air near the cloth, or wind cools the sun?
Solid → Liquid → Gas · Particle Arrangement
7. What causes gas pressure inside an inflated balloon: gas particles colliding with the inside walls of the balloon, or particles sticking together?
Solid → Liquid → Gas · Particle Arrangement
8. What is the change of state from a solid to a liquid when heated (e.g. ice turning into liquid water): melting or condensation?
Solid → Liquid → Gas · Particle Arrangement
9. At standard atmospheric pressure, at what temperature does pure liquid water boil into steam: 100 °C or 50 °C?
Solid → Liquid → Gas · Particle Arrangement
10. How does increasing the temperature of a liquid affect its rate of evaporation: it speeds up evaporation, or it stops evaporation?
Solid → Liquid → Gas · Particle Arrangement
11. Why does water expand slightly when it freezes into ice (making ice float on liquid water): water molecules form an open hexagonal crystal lattice, or ice gains extra atoms?
Solid → Liquid → Gas · Particle Arrangement
12. Does the total mass of an ice cube change when it melts completely in a sealed cup: No (mass is conserved) or Yes (it doubles)?
Solid → Liquid → Gas · Particle Arrangement
12 questions · Seed 44 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 7-9
Solids, liquids & gases
Answers and reasoning. Review before teaching.
1. Why does the smell of baking bread spread across a quiet room even without wind: diffusion (random particle motion from high to low concentration), or gravity?
Diffusion (random particle motion from high to low concentration)
Gas molecules move randomly and spread from higher concentration to lower concentration by diffusion.
2. Which metallic element is unusual because it is a liquid at standard room temperature (20 °C): mercury or iron?
Mercury
Mercury melts at −38.8 °C, so it is liquid at room temperature.
3. Which state of matter has a fixed volume but flows to take the shape of the bottom of its container: liquid or solid?
Liquid
Liquid particles stay close together but can slide past one another.
4. What is the change of state from a liquid to a solid when cooled: freezing (solidification) or evaporation?
Freezing (solidification)
Cooling removes thermal energy until liquid particles lock into a solid structure.
5. In which state of matter do particles have the highest average kinetic energy at a given pressure: gas (steam) or solid (ice)?
Gas (steam)
Particles in the gaseous state at higher temperature move fastest and have the greatest kinetic energy.
6. Why does a wet shirt dry faster on a windy day than on a still day: wind sweeps away humid air near the cloth, or wind cools the sun?
Wind sweeps away humid air near the cloth
Moving air removes water vapour near the fabric, maintaining a steep concentration gradient for evaporation.
7. What causes gas pressure inside an inflated balloon: gas particles colliding with the inside walls of the balloon, or particles sticking together?
Gas particles colliding with the inside walls of the balloon
Each particle collision exerts a tiny outward force on the container wall.
8. What is the change of state from a solid to a liquid when heated (e.g. ice turning into liquid water): melting or condensation?
Melting
Heating gives solid particles enough energy to break free of their fixed lattice and melt.
9. At standard atmospheric pressure, at what temperature does pure liquid water boil into steam: 100 °C or 50 °C?
100 °C
The normal boiling point of pure water is 100 °C.
10. How does increasing the temperature of a liquid affect its rate of evaporation: it speeds up evaporation, or it stops evaporation?
It speeds up evaporation
Higher temperature means more particles have enough kinetic energy to escape from the liquid surface.
11. Why does water expand slightly when it freezes into ice (making ice float on liquid water): water molecules form an open hexagonal crystal lattice, or ice gains extra atoms?
Water molecules form an open hexagonal crystal lattice
Hydrogen bonding in ice holds molecules slightly farther apart than in cold liquid water, lowering its density.
12. Does the total mass of an ice cube change when it melts completely in a sealed cup: No (mass is conserved) or Yes (it doubles)?
No (mass is conserved)
The same number of water molecules are present before and after melting, so mass is conserved.
12 questions · Seed 44 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 7-9
Solids, liquids & gases
Take your time. Show your thinking.
1. Why does the smell of baking bread spread across a quiet room even without wind: diffusion (random particle motion from high to low concentration), or gravity?
Solid → Liquid → Gas · Particle Arrangement
2. Which metallic element is unusual because it is a liquid at standard room temperature (20 °C): mercury or iron?
Solid → Liquid → Gas · Particle Arrangement
3. Which state of matter has a fixed volume but flows to take the shape of the bottom of its container: liquid or solid?
Solid → Liquid → Gas · Particle Arrangement
4. What is the change of state from a liquid to a solid when cooled: freezing (solidification) or evaporation?
Solid → Liquid → Gas · Particle Arrangement
5. In which state of matter do particles have the highest average kinetic energy at a given pressure: gas (steam) or solid (ice)?
Solid → Liquid → Gas · Particle Arrangement
6. Why does a wet shirt dry faster on a windy day than on a still day: wind sweeps away humid air near the cloth, or wind cools the sun?
Solid → Liquid → Gas · Particle Arrangement
7. What causes gas pressure inside an inflated balloon: gas particles colliding with the inside walls of the balloon, or particles sticking together?
Solid → Liquid → Gas · Particle Arrangement
8. What is the change of state from a solid to a liquid when heated (e.g. ice turning into liquid water): melting or condensation?
Solid → Liquid → Gas · Particle Arrangement
9. At standard atmospheric pressure, at what temperature does pure liquid water boil into steam: 100 °C or 50 °C?
Solid → Liquid → Gas · Particle Arrangement
10. How does increasing the temperature of a liquid affect its rate of evaporation: it speeds up evaporation, or it stops evaporation?
Solid → Liquid → Gas · Particle Arrangement
11. Why does water expand slightly when it freezes into ice (making ice float on liquid water): water molecules form an open hexagonal crystal lattice, or ice gains extra atoms?
Solid → Liquid → Gas · Particle Arrangement
12. Does the total mass of an ice cube change when it melts completely in a sealed cup: No (mass is conserved) or Yes (it doubles)?
Solid → Liquid → Gas · Particle Arrangement
12 questions · Seed 44 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 7-9
Solids, liquids & gases
Answers and reasoning. Review before teaching.
1. Why does the smell of baking bread spread across a quiet room even without wind: diffusion (random particle motion from high to low concentration), or gravity?
Diffusion (random particle motion from high to low concentration)
Gas molecules move randomly and spread from higher concentration to lower concentration by diffusion.
2. Which metallic element is unusual because it is a liquid at standard room temperature (20 °C): mercury or iron?
Mercury
Mercury melts at −38.8 °C, so it is liquid at room temperature.
3. Which state of matter has a fixed volume but flows to take the shape of the bottom of its container: liquid or solid?
Liquid
Liquid particles stay close together but can slide past one another.
4. What is the change of state from a liquid to a solid when cooled: freezing (solidification) or evaporation?
Freezing (solidification)
Cooling removes thermal energy until liquid particles lock into a solid structure.
5. In which state of matter do particles have the highest average kinetic energy at a given pressure: gas (steam) or solid (ice)?
Gas (steam)
Particles in the gaseous state at higher temperature move fastest and have the greatest kinetic energy.
6. Why does a wet shirt dry faster on a windy day than on a still day: wind sweeps away humid air near the cloth, or wind cools the sun?
Wind sweeps away humid air near the cloth
Moving air removes water vapour near the fabric, maintaining a steep concentration gradient for evaporation.
7. What causes gas pressure inside an inflated balloon: gas particles colliding with the inside walls of the balloon, or particles sticking together?
Gas particles colliding with the inside walls of the balloon
Each particle collision exerts a tiny outward force on the container wall.
8. What is the change of state from a solid to a liquid when heated (e.g. ice turning into liquid water): melting or condensation?
Melting
Heating gives solid particles enough energy to break free of their fixed lattice and melt.
9. At standard atmospheric pressure, at what temperature does pure liquid water boil into steam: 100 °C or 50 °C?
100 °C
The normal boiling point of pure water is 100 °C.
10. How does increasing the temperature of a liquid affect its rate of evaporation: it speeds up evaporation, or it stops evaporation?
It speeds up evaporation
Higher temperature means more particles have enough kinetic energy to escape from the liquid surface.
11. Why does water expand slightly when it freezes into ice (making ice float on liquid water): water molecules form an open hexagonal crystal lattice, or ice gains extra atoms?
Water molecules form an open hexagonal crystal lattice
Hydrogen bonding in ice holds molecules slightly farther apart than in cold liquid water, lowering its density.
12. Does the total mass of an ice cube change when it melts completely in a sealed cup: No (mass is conserved) or Yes (it doubles)?
No (mass is conserved)
The same number of water molecules are present before and after melting, so mass is conserved.
12 questions · Seed 44 · Age guidance, not curriculum certification