what is calciums ion
1. calcium ion-ion of calcium; a factor in the clotting of blood. factor IV. atomic number 20, Ca, calcium-a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals.. calcium ion-ion of calcium; a factor in the clotting of blood. factor IV. atomic number 20, Ca, calcium-a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals.