Definition of IGM. 1. : a class of immunoglobulins of high molecular weight including the primary antibodies that are released into the blood early in the immune response to be replaced later by IgG and that are highly efficient in binding complement.2.: an antibody of the class IgM.ADVERTISEMENT.efinition of IGM. 1. : a class of immunoglobulins of high molecular weight including the primary antibodies that are released into the blood early in the immune response to be replaced later by IgG and that are highly efficient in binding complement. 2. : an antibody of the class IgM. ADVERTISEMENT.
Calcium hydroxide is an Arrhenius base. You can see that it consists of a cation (we know calcium should be a cation because it is a metal on the left side of the periodic table bonded to elements on the right side). The anions are hydroxyl groups. #Ca(OH)_2->Ca^(2+)+2OH^-#.
Similarly, Arrhenius defined a base as a compound that increases the concentration of hydroxide ion (OHâ) in aqueous solution. Many bases are ionic compounds that have the hydroxide ion as their anion, which is released when the base dissolves in water.