<span>Everything in Earth's system can be placed into one of four major subsystems: land, water, living things, or air. These four subsystems are called "spheres." Specifically, they are the "lithosphere" land, "hydrosphere" water, "biosphere" living things, and "atmosphere" air. hope this helped </span>
2H(+) + SO4(2-) + Ca(2+) + 2I(-) -> CaSO4(s) + 2H(+) + 2I(-) The signs in brackets are the subscripts for the charge of the ion. This is the complete ionic equation. The net ionic equation is: Ca(2+) + SO4(2-) -> CaSO4
