Question

please complete these questions. take your time to make sure you understand the question and have the proper number of answers. 1. choose the words to complete the sentences. 2 answers a change in the thermal energy of a substance can lead to a change of state. for example, when heat is added to a solid, its particles move (slower, faster, closer together, the same speed). once the solid gains enough thermal energy, it can change to a (solid, liquid, frozen, gas, state).

Explanation:

When heat is added to a solid, the thermal energy increases. According to the kinetic - molecular theory, an increase in thermal energy leads to an increase in the kinetic energy of the particles. Kinetic energy is related to the speed of the particles ($KE=\frac{1}{2}mv^{2}$, where $KE$ is kinetic energy, $m$ is mass, and $v$ is speed). As the mass of the particles in a solid is constant (at least for the simple case of a pure substance undergoing a phase change), an increase in $KE$ means an increase in $v$, so the particles move faster.

For the second blank, the phase change of a solid when it gains enough thermal energy is melting. The product of melting is a liquid. A solid - to - solid change (like a change in crystal structure) is not what is described here. A frozen state is just another term for a solid. A gas is the product of vaporization (from liquid) or sublimation (from solid, but that requires more energy than just melting in most common substances). And “state” is too general.

Answer:

faster, liquid