The correct answer is A. is a measure of the hydrogen ion concentration.
Explanation:
The pH determines how acid or alkaline a substance is, usually by classifying substances and mainly solutions on a scale from 0 to 14, in which 7 represents a neutral substance. This property is determined based on the hydrogen ion concentration, in this way a substance with a high hydrogen ion concentration is more acid that one with a low hydrogen ion concentration. Additionally, in this scale solutions are classified as acidic if they have a pH lower than 7 or as basic if the pH is higher than 7. According to this, it can be concluded pH is a measure of the hydrogen ion concentration.
The word sponge is more appropriate to use than Underground river since an underground river can loose water while an aquifer cannot loose water, unless it is open-air and above ground. then the aquifer would slowly loose water due to evaporation from the sun.
In a habitat there are red bugs and green bugs. The birds prefer the taste of the red bugs, so soon there are many green bugs and few red bugs. The green bugs reproduce and make more green bugs and eventually there are no more red bugs.
