|In Jupiter, the hydrogen in the atmosphere is in
the gas phase. As you go towards the center of
Jupiter, the hydrogen undergoes a phase transition
to the liquid phase. Why does this happen?|
|Question Date: 2018-07-11|
The reason is because of pressure. You can
go on a THOUGHT EXPERIMENT diving deeper and
deeper into the “atmosphere” of Jupiter. Start at
the top where the mixture of H2 and He
(diatomic hydrogen gas and Helium) are very low
density. As you travel deeper because there is
more and more H2 and He above you,
the PRESSURE increases. Now, as the pressure
increases t,he density of the gas mixture
increases when the pressure exceeds a certain
value (that is when you are deep enough), the gas
mixture converts to a liquid, .this is a
pressure effect. Finally at still higher
pressure the liquid mixture becomes solid!!!
When pressure increases on any material the
atoms that make up the stuff get closer and closer
together. This “getting closer” means that the
density increases. The density of any
material is DEFINED as the mass of the stuff
per unit volume.
So, the density of water vapor is rather low like
1 kg per cubic meter… as the gas compresses it
eventually becomes a liquid water with density
1000 kg cubic meter.
I hope this helps.
In Jupiter, the hydrogen in the atmosphere is in
thegas phase. As you go towards the center
of Jupiter, the hydrogen undergoes a phase
transition to the liquid phase.
Why does this happen?
Hydrogen, and materials in general, will change
between solid, liquid, and gas phases with
temperature and pressure. In the case of
descending toward the center of Jupiter, it is the
increase in pressure which causes the
transition. The pressure on some area within
Jupiter's atmosphere is the weight of the
atmosphere above it (attracted toward the center
of Jupiter by gravity -
the same thing happens on Earth, and
anywhere else with an atmosphere).
In the outer atmosphere, there is very little
that is higher and pressing down on the gas, so
the pressure is low and the gas molecules are able
to move around without interacting. As the
pressure is increased, the molecules are forced
closer together and start to interact with each
other. Eventually it is more favorable for
them to interact and stick close together rather
than be spread out, and then we call it a
Phase transitions can happen because of changes
in temperature, such as when water freezes or
boils. But phase changes can also happen
because of changes in pressure. Water, for
example, boils at lower temperatures up in the
mountains, but it boils at higher temperatures
near sea level. Further away from Jupiter’s center
there are lower gas pressures and temperatures,
low enough that any liquid hydrogen boils. Further
towards Jupiter’s center the pressure and
temperature increase enough that liquid hydrogen
can exist; it is stable there.
The pressure inside Jupiter is so high, that it
"compresses" the gas hydrogen into a liquid
hydrogen. When the pressure increases,
the density of states of matter also
increases, and the liquid hydrogen has a much
higher density than gas. In fact, the same
phenomenon happens to steam and water.
Increasing pressure on steam also turns it into
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