Which of the following factors can cause a substance to transition between the solid and liquid states?

• A. Addition of a catalyst
• B. Increase in volume
• C. Changes in temperature and pressure
• D. Exposure to ultraviolet light

Answer: (C)

Verified step by step guidance

1. Understand that phase transitions between solid and liquid states depend primarily on changes in temperature and pressure, which affect the energy and arrangement of particles in a substance.
2. Recognize that adding a catalyst does not influence phase changes because catalysts only affect the rate of chemical reactions, not physical state changes.
3. Know that increasing volume alone does not directly cause melting or freezing; instead, pressure changes (which relate to volume changes in gases) can influence phase transitions.
4. Identify that exposure to ultraviolet light can provide energy to molecules but typically causes chemical reactions or electronic excitations rather than direct phase changes between solid and liquid.
5. Conclude that the correct factors causing transitions between solid and liquid states are changes in temperature (which provide or remove heat) and pressure (which affects particle proximity and phase stability).