Question Video: Relating Particle Diagrams to Temperature Science • First Year of Preparatory School

Video Transcript

The diagram below shows a progressive change of state. Which of the arrows indicates an increase of temperature?

Increasing the temperature increases the thermal energy of a system. An increase in thermal energy leads to an increase in the speed of the particles and the distance between them. If we look at the system on the right, the particles are represented as compact and slow moving. This particle diagram likely represents a solid. The particles in the system on the left are represented as spread out and fast moving. This particle diagram likely represents a gas. The particle diagram in the middle, which has fast-moving particles that are more spread out than a solid but less spread out than a gas, likely represents a liquid.

To answer the question, we want to know which of the arrows, A or B, indicates an increase of temperature. As particles’ speed and the distance between the particles increases with increasing temperature, the temperature must be increasing from right to left. Therefore, the arrow that indicates an increase of temperature is arrow B.