
What it is
A measure of how acidic or alkaline an aqueous solution is. On the commonly used scale, 7 is neutral at room temperature, lower values are acidic and higher values alkaline; the scale is logarithmic and is not strictly limited to 0–14.

What it is
A measure of how acidic or alkaline an aqueous solution is. On the commonly used scale, 7 is neutral at room temperature, lower values are acidic and higher values alkaline; the scale is logarithmic and is not strictly limited to 0–14.