Calcium carbonate equilibrium pressure must exceed total atmospheric pressure of 101 kPa, which happens at 898 °C. Calcium carbonate is poorly soluble in pure water (47 mg/L at normal atmospheric CO partial pressure as shown below). The equilibrium of its solution is given by the equation (with dissolved calcium carbonate on the right): where the solubility product for [Ca] [CO] is given as anywhere from "K" = 3.7×10 to "K" = 8.7×10 at 25 °C, depending upon the data source. What the equation means is that the product of molar concentration of calcium ions (moles of dissolved Ca per liter of solution)
Symbol Hence, "outward sign" of something. The meaning "something which stands for something else" was first recorded in 1590, in Edmund Spenser's "Faerie Queene". In considering the effect of a symbol on the psyche, in his seminal essay "The Symbol without Meaning" Joseph Campbell proposes the following definition: "A symbol is an energy evoking, and directing, agent". Later, expanding on what he means by this definition Campbell says: Jared Elisha defined symbolism that is something that stands for another, it can be place, object, or a person Heinrich Zimmer gives a concise overview of the nature, and perennial relevance, of symbols.