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 ...

Electrochemical water splitting, which yields only hydrogen and oxygen, presents a cleaner alternative. While proton exchange membrane ... to high concentrations of potassium hydroxide at 80 ...

4th Period: Potassium and Calcium—Electrons go into the fourth energy level. A small piece of sodium metal is placed in water. The sodium reacts with the water and gets very hot, producing sodium ...