Video Transcript
What is the name given to the
process in which sublimation is reversed?
To figure out what this name is,
let’s first consider what the process of sublimation is. The word sublimation has to do with
states of matter, in particular, with transitioning from one state of matter to
another. We can recall that the three
primary states of matter are solids, liquids, and gases.
From experience, we know that it’s
possible for a material to change states. That is, if it starts in one state
of matter, say as a liquid, then it’s possible for it to transition either to a gas
or to a solid. It doesn’t always have to stay in
the same state of matter. These transitions between states of
matter have been given names. For example, when a liquid becomes
a gas, that’s called evaporation. And when a liquid turns into a
solid, that’s known as freezing.
This name, we’ve been given in the
problem statement, sublimation, is the name for another type of phase change. Sublimation is what occurs when we
start out as a solid. And then, instead of going from a
solid to a liquid, we jump the liquid phase and go straight to the gas phase. If you’ve ever seen water vapour
rising off of a frozen block of ice, then you’ve seen sublimation in action, going
from a solid straight to a gas phase.
Our question asks what’s the name
given to the process which is the reverse or the opposite of sublimation. In other words, if we start out as
a gas and then transition straight to a solid without going through the liquid
phase, there is a name for that process. And the name is deposition. This is the name we give to the
process when a gas changes state to become a solid, without becoming a liquid
first.