Question

Why does ice change to water as energy is added at the melting point?

a. Kinetic energy is removed from the molecules, so they separate.
b. Molecular motion decreases until the temperature begins to increase.
C. Molecules vibrate quicker, and their motion overcomes the forces of attraction.
d. All the forces of attraction between molecules disappear at the melting point.​

Answer 1

C. Molecules vibrate quicker, and their motion overcomes the forces of attaraction.

Step-by-step explanation:

Temperature remains constant as the ice gradually changes to liquid state; melting point. It remains constant as the increased kinetic energy it had acquired makes its molecules vibrate vigorously causing further weakening between the molecules. Therefore, the ice changes to water as energy is added at the melting point.

Answer 2

C.

Step-by-step explanation:

Melting happens when the molecules of a solid gain enough momentum that the motion overcomes the attractions, allowing the molecules to move. Molecular motion does not decrease; this occurs when liquid freezes. Neither will it 'disappear'.

This motion comes from kinetic energy is being added to the molecules, not removed. This 'excites' the particles, which breaks the bonds that hold them together, which results in solid melting into water.

Therefore A, B, and D are incorrect, making C correct.