Osmosis which is a form of passive transport

represents the flow of water through its concentration gradient, through a semi-permeable membrane.

Explanation:

This means that water flows from where it is in a higher concentration to a place where it is in a lower concentration to try to equalize the concentrations of both solutions.

Osmosis is an example of diffusion when molecules tend to be evenly distributed in space.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%