any of the major appearances or aspects in which a thing of varying modes or conditions manifests itself to the eye or mind. 2. a stage in a process of change or development: Each phase of life brings its own joys. 3. a side, aspect, or point of view: This is only one phase of the question.
The pH of a neutral solution is 7. At this pH, the solution has equal concentrations of both the H+ and OH- ions, which is 10^-7 mole/litre. The presence of both the hydrogen and hydroxyl ions in equimolar concentrations makes the solution neutral.
Soil pH is a measure of acidity (hydrogen ion concentration). The pH values range from 0 to 14: 0 is most acidic, 7 is neutral, and 14 is most basic (lowest hydrogen ion concentration). Soil pH values range from ~3 to 10. Forest and bog soils of the humid east tend to be acidic and grassland and desert soils of the west tend to be basic.