Gas Particles, Diffusion & Pressure — Drills · Grade 8 Science
Chapter: Phases of MatterWhat these drills covers
By the end of Gas Particles, Diffusion & Pressure you should be able to:
- I can explain diffusion and gas pressure with particle motion and collisions.
- I can test a fixed-amount, matched-temperature pressure–volume model and identify its limits.
4 questions, written answer, each with a worked explanation.
Vocabulary used: diffusion, concentration, gas pressure, compression, absolute pressure, model, evidence, system boundary, assumption.
Problem 1
Answer and explanation
No. Individual particles move in varying directions. The overall distribution changes because more particles start in one region than another.
No. Individual particles move in varying directions. The overall distribution changes because more particles start in one region than another.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 2
Answer and explanation
The particles have less space and collide with the walls more frequently under comparable temperature conditions, increasing the pressure.
The particles have less space and collide with the walls more frequently under comparable temperature conditions, increasing the pressure.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 3
Answer and explanation
Particle number and temperature are assumed fixed. Volume changes, while particle size does not. A leaking syringe would not meet the fixed-particle assumption.
Particle number and temperature are assumed fixed. Volume changes, while particle size does not. A leaking syringe would not meet the fixed-particle assumption.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 4
Answer and explanation
Both temperature and volume change. Either can influence pressure, so the difference would not isolate temperature.
Both temperature and volume change. Either can influence pressure, so the difference would not isolate temperature.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.