Calcium is a silvery-white metal; it is relatively soft, but much harder than sodium metal. Calcium is a member of the alkaline-earth metals Group II on the periodic table ; these metals react vigorously with water, although not as violently as the Group I metals such as sodium or potassium:. In the following demonstration, a chunk of calcium metal is dropped into a beaker of distilled water.
After a second or so, the calcium metal begins to bubble vigorously as it reacts with the water, producing hydrogen gas, and a cloudy white precipitate of calcium hydroxide. The presence of the hydroxide is demonstrated by the addition of a few drops of phenolphthalein indicator, which turns the solution pink, indicating that the solution is basic. In limed soils calcium may immobilize iron. This may cause iron shortages, even when plenty of iron is present in the soil.
Water hardness influences aquatic organisms concerning metal toxicity. In softer water membrane permeability in the gills is increased. Calcium also competes with other ions for binding spots in the gills. Consequently, hard water better protects fishes from direct metal uptake. Various calcium compounds may be toxic. Calcium carbide forms flammable ethyn when it comes in contact with water and is therefore considered hazardous.
Some environmental effects of water hardness include hardening of domestic equipment, because high temperatures cause carbonate hardness. This may dramatically decrease the lifespan of equipment, and causes an increase of domestic waste. Calcium carbonate interacts with detergents and cleansing agents. Complex formation causes a decrease in detergent efficiency, resulting in requirement for increased detergent application and softener purchases see also magnesium and water.
Softening is often carried out by means of ion exchangers. These must be regenerates with kitchen salt, and therefore burden wastewater. There are six stable calcium isotopes. Today, we know of eight instable calcium isotopes. What are the health effects of calcium in water? Calcium is a dietary mineral that is present in the human body in amounts of about 1.
No other element is more abundant in the body. Calcium phosphate is a supporting substance, and it causes bone and tooth growth, together with vitamin D. Calcium is also present in muscle tissue and in the blood. It is required for cell membrane development and cell division, and it is partially responsible for muscle contractions and blood clotting.
Calcium regulates membrane activity, it assists nerve impulse transfer and hormone release, stabilizes the pH of the body, and is an essential part of conception.
In order to stimulate these body functions a daily intake of about mg of calcium is recommended for adults. This may be achieved by consuming dairy, grains and green vegetables. Calcium carbonate works as a stomach acid remedy and may be applied to resolve digestive failure. Calcium lactate may aid the body during periods of calcium deficiency, and calcium chloride is a diuretic. Calcium reacts slowly with water.
This is in contrast with magnesium, immediately above calcium in the periodic table, which is virtually unreactive with cold water. The reaction forms calcium hydroxide, Ca OH 2 and hydrogen gas H 2. The calcium metal sinks in water and after an hour or so bubbles of hydrogen are evident, stuck to the surface of the metal.
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