it is a genetic way of telling your brain to focus.
A very strong Acid --- or Base-. A pH=7 reading means an equal concentration of H+ and OH-. A pH reading of say 1 shows a very high concentration of H+ with an exceedingly low concentration of OH-.
high to low.
osmosis
i am not sure but i do know that in diffusion particles move from a high concentration to a low concentration!.
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