Grade 6 · Science
Use a particle model of matter
Connect a stated particle model with shape, volume and diffusion observations.
6 authored questions + worked example
Worked example
Model S has particles close together, vibrating around fixed positions. Which behavior best matches this solid model?
Answer & why
Answer: It keeps a definite shape.
Fixed relative positions explain the definite shape; vibration is still motion.
All questions
All 6 authored questions for this skill.
Question 1
Model G has widely spaced particles moving in many directions. Which behavior best matches this gas model?
- It spreads through the available space.
- It has no mass.
- It has a fixed rigid outline.
- It is always visible.
A hint
Use the particle arrangement described; a model represents behavior without being a picture of every particle.
Answer & why
Answer: It spreads through the available space.
Widely spaced moving particles can occupy the available volume.
Question 2
Two gases begin on opposite sides of a container. After a barrier is removed, their particles mix through random motion. What is this mixing called?
- Cutting
- Diffusion
- Freezing
- Magnetic attraction
A hint
Use the particle arrangement described; a model represents behavior without being a picture of every particle.
Answer & why
Answer: Diffusion
Diffusion is spreading and mixing through particle motion.
Question 3
A model shows blue dots representing water molecules. Which statement recognizes a model limitation?
- Every real molecule is the same size as the drawing.
- A useful model must show every molecule individually.
- The model proves water contains blue paint.
- Real molecules are not necessarily blue dots of that drawn size.
A hint
Use the particle arrangement described; a model represents behavior without being a picture of every particle.
Answer & why
Answer: Real molecules are not necessarily blue dots of that drawn size.
The dots are representations; their chosen color and scale are not literal measurements.
Question 4
A sealed syringe contains gas. Its volume decreases when the plunger moves in. In the widely spaced-particle model, what decreases most directly?
- The mass of every particle.
- The identity of every particle.
- The number of particles, despite no leak.
- The space between particles.
A hint
Use the particle arrangement described; a model represents behavior without being a picture of every particle.
Answer & why
Answer: The space between particles.
Compression brings particles closer without requiring matter to leave.
Question 5
Model S has particles close together, vibrating around fixed positions. Which behavior best matches this solid model?
- Its particles do not move at all.
- It contains no matter.
- It must fill every available container.
- It keeps a definite shape.
A hint
Use the particle arrangement described; a model represents behavior without being a picture of every particle.
Answer & why
Answer: It keeps a definite shape.
Fixed relative positions explain the definite shape; vibration is still motion.
Question 6
Model L has particles close together that can move past one another. Which behavior best matches this liquid model?
- It has no particles.
- It takes the container's shape while retaining its volume.
- It always keeps a rigid shape.
- It must spread to fill an entire room.
A hint
Use the particle arrangement described; a model represents behavior without being a picture of every particle.
Answer & why
Answer: It takes the container's shape while retaining its volume.
Particles can rearrange while remaining close together.
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