<span>A. the measure of the acidity or alkalinity of soil Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize an acid.</span>
There are different types of observers. Casual observers differ from scientific observer. Seeing and observing are two different things. Not that everybody seeing is actually observing the thing.
A casual observer just sits back and watch for something to happen while a scientific observer comes up with some hypothesis to work on it.