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 the states in each region

• Region 1: The substance is in the solid state. Particles are closely packed in an orderly arrangement.
• Region 2: Melting process. Solid and liquid co - exist.
• Region 3: Liquid state. Particles are close but can move around.
• Region 4: Boiling process. Liquid and gas co - exist.
• Region 5: Gas state. Particles are far apart and move freely.

Step2: Match the particle representations

• The first particle representation (mostly solid - like arrangement at the bottom) matches Region 1 (solid).
• The second particle representation (solid - liquid mixture) matches Region 2 (melting).
• The third particle representation (liquid - like close but disordered arrangement) matches Region 3 (liquid).
• The fourth particle representation (liquid - gas mixture) matches Region 4 (boiling).
• The fifth particle representation (gas - like far apart particles) matches Region 5 (gas).

Answer:

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