Well when a particle of air is becomes heated it rises, right? So you could write some like you started off close to the earth (aka the troposphere) until you became heated then you started to rise and as you reached higher elevations you cooled down and you were recycled into cool air and you moved back down and became new fresh cool air until the next time you'll become heated and rise again to be recycled into fresh cool new air.
The reactivity of a metal is determined by how tightly the metal holds onto the electrons in the outermost energy levels (valence electrons)
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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:
Covalent solids, also called network solids, are solids that are held together by covalent bonds. As such, they need localized electrons (shared between the atoms) and therefore the atoms are arranged in fixed geometries. Distortion far from this geometry can only occur through a breaking of covalent sigma bonds.
All the information is answered/given in the paragraph except that the study doesn’t show cells in their natural habitat!
