For instance, potassium can be replaced by cations such as calcium or hydrogen, and vice versa. The total number of cations a soil can hold--or its total negative charge--is the soil's cation exchange ...

The sulfonic or carboxylic groups may be saturated initially with hydrogen, ammonium, sodium, potassium or calcium or combinations of these ions, the exact choice depending chiefly on the clinical ...

Sodium becomes a positive ion and chlorine becomes a negative ion. The positive and negative ions attract each other and form the ionic compound sodium chloride. One calcium and two chlorine atoms are ...