Which action occurs as a substance undergoes a phase change from a solid to a liquid? explain
a
The intermolecular attractive forces are broken by the addition of heat.
b
The temperature of the particles decrease because heat is being added.
c
The temperature of the particles increase because heat is being added.
d
The substance changes into a completely different substance. The particles of the original substance are destroyed and new particles form.
The correct answer is option a: The intermolecular attractive forces are broken by the addition of heat.
When a substance undergoes a phase change from a solid to a liquid, it means it is melting. This transition occurs when heat is added to the solid substance, which increases its internal energy. As the particles gain energy, the intermolecular forces holding them in a fixed arrangement start to weaken and break. This allows the particles to move more freely and take up a more disordered arrangement, resulting in a liquid state. So, the breaking of the intermolecular attractive forces is the key action that occurs during this phase change.