Let me work through these questions step by step.
Question 1: When water is warmed, what happens to its molecules?
When you heat water (or any substance), the molecules gain energy. This extra energy makes them move faster - they vibrate more vigorously and move around more quickly.
However, the actual SIZE of individual molecules doesn't change when heated. The molecules themselves stay the same size - it's just that they move faster and spread out more, which is why substances expand when heated. But each individual molecule maintains its original size.
So looking at the options:
- A: faster movement, decreases size - WRONG (size doesn't decrease)
- B: faster movement, stays the same size - CORRECT
- C: slower movement, decreases size - WRONG (movement gets faster, not slower)
- D: slower movement, stays the same size - WRONG (movement gets faster)
Question 2: For which states can diffusion be demonstrated using simple laboratory apparatus?
Looking at the diagrams:
- Diagram 1 shows particles tightly packed in regular rows = SOLID
- Diagram 2 shows particles close together but not in fixed positions = LIQUID
- Diagram 3 shows particles far apart and spread out = GAS
Diffusion is the movement of particles from areas of high concentration to low concentration. Let's think about which states allow this:
-
Solids: Particles are locked in place and can only vibrate. They cannot move freely, so diffusion essentially doesn't occur in solids (or occurs extremely slowly over very long periods). You can't demonstrate solid diffusion with simple lab equipment.
-
Liquids: Particles can move past each other. Diffusion definitely occurs in liquids - for example, if you drop food coloring in water, it spreads throughout. This can easily be shown with simple lab apparatus.
-
Gases: Particles move freely and rapidly. Diffusion occurs very quickly in gases - like when you spray perfume and smell it across the room. This can also be demonstrated with simple lab equipment.
So diffusion can be demonstrated for liquids (diagram 2) and gases (diagram 3), but not for solids (diagram 1).
The answer is C: 2 and 3
Final Answer:
1. B
2. C
Parent Tip: Review the logic above to help your child master the concept of nature of matter worksheet.
