The expansion of gases takes place because of kinetic energy provided by heat which excites the molecules and causes them to move further apart. On cooling the atoms in a gas lose their energy and slow down coming closer together.
We can explain this in a molecular level. We know that the difference between a gas and a liquid of the same composition is how fast their molecules are moving. So given a gas, their molecules are farther and faster when moving, but when they are cooled their bulk kinetic energy decreases. In other words their molecules start to move closer and move slower until it behaves more like a liquid molecule. This is the time when gases condense
Nitrogen seems to be much difficult for plants to acquire because they can only consume nitrogen when it is combined with oxygen or hydrogen, which is why tropical forests have a lusher plant growth than tundra.
The decomposition process is the secret to maintaining the nitrogen cycle going since the bulk of fixed nitrogen arrives from decaying organisms and faces being broken down by bacteria.
Plant cells are enclosed by a rigid cell wall. When the plant cell is placed in a hypotonic solution , it takes up water by osmosis and starts to swell, but the cell wall prevents it from bursting.
