Video Transcript
Three states of matter are shown in
containers (A), (B), and (C). What change will occur during the
process of melting?
The process of melting is the
change of matter from the solid state to the liquid state when it gains enough
thermal energy. The particles in a solid are
closely packed together. These particles have energy and do
move, but they essentially stay in one spot as they vibrate and rotate. So, the image that most likely
represents matter in the solid state is image (A).
When matter gains thermal energy,
the intermolecular distance between the particles increases. So, in the liquid state, the
particles are less tightly packed than they are in the solid state. The increase in thermal energy also
means that particles in the liquid state move about more freely than they do in the
solid state. Figures (B) and (C) show spread-out
particles that have more movement than the particles in box (A). So, which of these figures
represents a liquid?
Let’s consider the third state of
matter, the gaseous state. Of the three states of matter, the
particles in the gaseous state are the most spread out and have the most
movement. So, figure (C) must represent a gas
and figure (B) must represent a liquid. We know that during melting a solid
turns into a liquid. Therefore, the change that will
occur during the process of melting is (A) to (B).
