Question

consider the heating curve of h2o and line segments a, b, and c. several changes are taking place at a, b, and c. all but one would be an appropriate description as we move through segments a, b and then c.
a temperature is increasing.
b kinetic energy is increasing.
c space between molecules decreases.
d molecular attraction is decreasing.

Explanation:

• In segment A, as heat is added to the solid water (ice), temperature increases and so does kinetic energy as molecules move faster.
• In segment B, during the phase - change from solid to liquid (melting), heat is used to break intermolecular forces, molecular attraction decreases, and space between molecules increases as it changes from a more ordered solid state to a less - ordered liquid state. Kinetic energy remains constant during the phase - change as temperature is constant.
• As we move from solid to liquid, the space between molecules increases, not decreases.

Answer:

C. Space between molecules decreases