When you breathe, the pressure inside the lungs is different than the pressure outside the lungs. This is an example of a(n) . When you breathe, the pressure inside the lungs is different than the pressure outside the lungs. This is an example of a(n) . concentration gradient pressure gradient electrical gradient temperature gradient

pressure gradient

Explanation:

The correct answer would be pressure gradient.

A pressure gradient is created when there is a difference in the amount of pressure between two points or locations that are adjacent to one another.

In this case, the two locations that are adjacent to one another are the inside and outside of the lung. When one breathes in, the pressure inside the lung is more than that of the outside and the lung expands as a result. When we breathe out, the pressure outside is more than that of the inside and the lung collapses.  

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