Question

how does the movement of molecules inside a solid block of iron change as the iron is heated? the molecules move faster. the molecules move slower. the molecules stop moving completely. the molecules move in the same way at all temperatures.

Explanation:

When a solid like iron is heated, the thermal energy is transferred to its molecules. According to the kinetic - molecular theory, an increase in temperature leads to an increase in the kinetic energy of molecules. So, the molecules move faster.

Answer:

The molecules move faster.