00:03
Hi there.
00:04
In this question, we want to know which phase changes are occurring here at point b.
00:11
Point b on this phase diagram is known as the triple point.
00:21
And the triple point is the pressure and temperature where all three states of matter exist at equilibrium or in equilibrium.
00:37
So that is solid, liquid, and gas.
00:53
So at equilibrium, remember, it is not static.
00:57
In an equilibrium, the rate of exchange is equal.
01:02
Well, if we have all three states of matter existing here at equilibrium, that means we are going to have solids changing to a gas, which is sublimation.
01:14
But at the same time, we're going to have gases changing back to solid, which is deposition.
01:22
We're also going to have changes from solid to liquid, which we know of is melting, and from liquid back to solid.
01:32
Which we know as freezing.
01:37
Similarly, since we also have liquid and gas in equilibrium, that means we have vaporization and condensation.
01:56
So since the three states of matter are at equilibrium, all of these phase changes are occurring.
02:07
All right.
02:08
So all of these would be the answer.
02:11
As we look at your answer choices, what came through are just four choices...