Which term describes the phase change from solid to liquid?

Which term describes the phase change from solid to liquid?

• A. Fusion
• B. Freezing
• C. Condensation
• D. Sublimation

Answer: (A)

When a solid changes into a liquid, energy is added to the solid to overcome the forces holding its particles in a rigid structure. This transition to a more disordered, fluid state is called fusion (also known as melting). During fusion, the temperature remains at the melting point while heat is absorbed until all of the solid becomes liquid, because that energy goes into breaking bonds rather than increasing temperature (latent heat of fusion). The other terms describe different transitions: freezing is liquid to solid, condensation is gas to liquid, and sublimation is solid to gas. So the solid-to-liquid term is fusion.

When a solid changes into a liquid, energy is added to the solid to overcome the forces holding its particles in a rigid structure. This transition to a more disordered, fluid state is called fusion (also known as melting). During fusion, the temperature remains at the melting point while heat is absorbed until all of the solid becomes liquid, because that energy goes into breaking bonds rather than increasing temperature (latent heat of fusion). The other terms describe different transitions: freezing is liquid to solid, condensation is gas to liquid, and sublimation is solid to gas. So the solid-to-liquid term is fusion.