The apparatus below is used to react calcium with water and collect the gas. This would not be used with sodium or potassium as they float and the reaction is too vigorous.

A little water helps expose the sodium so it can react with the chlorine gas. The reaction releases a lot of heat as the ... The positive and negative ions attract each other and form the ionic ...

A water softener reduces the dissolved calcium, magnesium, and to some degree manganese and ferrous iron ion concentration in ...