Question

a substance is placed in a closed vessel. the substance is continuously heated and its temperature is monitored, leading to the heating curve below. five regions of the heating curve are labeled with a number. match each particle representation to a numbered region of the graph.

Explanation:

Step1: Analyze each region

• Region 1: Solid state (low - energy, closely - packed particles).
• Region 2: Melting (solid - liquid co - existence).
• Region 3: Liquid state (particles have more energy than solid, less ordered than gas).
• Region 4: Boiling (liquid - gas co - existence).
• Region 5: Gas state (high - energy, widely - spaced particles).

Step2: Match particle representations

• The first particle representation (mostly closely - packed at the bottom) matches Region 1 (solid).
• The second particle representation (some closely - packed at the bottom and some spaced out) matches Region 2 (melting - solid and liquid).
• The third particle representation (all closely - packed in a vertical arrangement) matches Region 3 (liquid - more ordered than gas).
• The fourth particle representation (partly closely - packed and partly with some space) matches Region 4 (boiling - liquid and gas).
• The fifth particle representation (all widely - spaced) matches Region 5 (gas).

Answer:

First particle representation: Region 1; Second particle representation: Region 2; Third particle representation: Region 3; Fourth particle representation: Region 4; Fifth particle representation: Region 5.