Soil pH Soil pH Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. pH is defined as the negative logarithm (base 10) of the activity of hydronium ions ( or, more precisely, ) in a solution. In soils, it is measured in a slurry of soil mixed with water (or a salt solution, such as 0.01 M ), and normally falls between 3 and 10, with 7 being neutral. Acid soils have a pH below 7 and alkaline soils have a pH above 7. Ultra-acidic soils (pH < 3.5) and very strongly alkaline soils (pH > 9)
Alkali metal halide temperatures above the melting point. The table below provides links to each of the individual articles for these compounds. The numbers beside the compounds show the electronegativity difference between the elements based on the Pauling scale. The higher the number is, the more ionic the solid is. Alkali metal halide Alkali metal halides (also known as alkali halides) are the family of inorganic compounds with the chemical formula MX, where M is an alkali metal and X is a halogen. These compounds are the often commercially significant sources of these metals and halides. The best known of these compounds is