Question

what is the relationship between the internal energy of a substance and its state of matter?
a as a gas loses internal energy it becomes a plasma
b closer packed atoms generally have more internal energy
c as the internal energy decreases a substance will spread further apart
d as the internal energy increases a substance will go from solid to liquid to gas

Explanation:

To solve this, we analyze the relationship between internal energy and states of matter (solid, liquid, gas) using the particle diagrams. Internal energy relates to particle motion and spacing.

• Option A: Talks about gas to plasma, not about solid - liquid - gas internal energy relationship, so incorrect.
• Option B: Closer - packed (solid) has less internal energy than liquid/gas, so "closer packed atoms have more internal energy" is wrong.
• Option C: As internal energy increases, particles move more, spread further (solid → liquid → gas: particles get farther). This matches the diagram (solid particles close, liquid more spread, gas most spread) and internal energy concept (more energy = more motion/spacing).
• Option D: If internal energy decreases, particles should come closer (gas → liquid → solid), not "be more spread", so incorrect.

Answer:

C. As the internal energy increases a substance will spread further apart