<span>
When air is warmed up, its molecules move faster and faster and as a
result they move further from each other. They still have the same
mass, but they now occupy a larger volume. This means that its density
is smaller.
The opposite when air is cooled off. The molecules slow down, get
closer together, occupy a smaller volume and therefore its density is
bigger.
When air is warmed up, it goes up. Once it's up there, is cools off and
goes back down. Near the heated surface the air gets warmed up again,
goes up, cools down, goes back down, and again and again.
that is called convection cells
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Answer:
liquid at room temperature
mercury is an exception to that though
Answer:
407pm is the edge length of the cubic unit cell
Explanation:
In a Face-centered cubic unit you can use Pythagoras theorem to relate edge length with atomic radius (As you can see in the picture), thus:
e²+e² = (4r)²
2e² = 16r²
e = √8 r
If the atomic radius of the atom is 144pm:
e = √8 ×144pm
e = 407ppm
407pm is the edge length of the cubic unit cell
When the Earth's surface absorbs the sun's energy, it turns the light into heat. This heat on Earth's surface warms the air above it. The air over the Equator gets warmer than the surface air near the poles. This moving air is what we call wind.
Mark brainless if possible :) Have a good day !
