Calcium is a very reactive chemical element. That's why it is only found in nature in conjunction with other substances. For example, calcium is contained in gypsum or in rocks such as marble or limestone. The element is also an essential component of teeth and bones.
In terms of mass fraction of the earth's shell, calcium is the fifth most common element found in the world.
Calcium is a chemical element with the atomic number 20 and the element symbol Ca, which belongs to the group of alkaline earth metals. Calcium is a divalent cation , which is important in water treatment , especially when water softening through ion exchange . Due to its bivalent nature, the exchange resin in a softening system strives to absorb calcium from the water and exchange it for monovalent sodium . In addition to calcium, the exchange resin of a softening system also absorbs magnesium . The two substances calcium and magnesium are responsible for hard water and therefore limescale deposits.
Chemical properties
The element belongs to the alkaline earth series. It is a base metal with enormous reactivity. If you disperse it finely, it can even self-ignite when exposed to air.
The metal also reacts quickly with the oxygen present in the air. If you leave it unprotected in the air for a long time, a white oxidation layer will form on the surface.
The element has a melting temperature of 838°C and begins to boil at 1490°C.
Calcium is an extremely soft metal with a silver color.
Calcium affects water hardness
Water naturally contains a certain amount of calcium. The calcium content is, among other things, crucial for the hardness of the water. The more calcium there is in water, the harder it is. Too much lime , which is a calcium compound, in the water can be harmful to household appliances, which is why you should use special descalers for particularly hard water.
The hardness of the water also plays a role in the taste of the water. Especially for tea or coffee you use tap water and not mineral water. Hard water has a less pleasant taste than soft water. That's why it's worth installing a water softening system if you live in a region with particularly hard tap water .
Calcium is good for the body
The recommended amount of calcium in healthy mineral water for children and health-conscious people is 150 to 250 mg per liter of water. However, there is no legally regulated limit that should not be exceeded.
It is particularly important for children to ensure adequate calcium intake as they are still growing. The element is also an important component of bones and teeth and is required for their structure. If children don't absorb enough of the substance, their bones can break more easily because they are too soft.
Calcium is also an important nutrient for adults and should be consumed in sufficient quantities. A daily amount of 800 to 1000 mg is recommended. In addition to its importance for teeth and bones, the element is also responsible for the formation of new cells. It also helps to keep the pH value of the human body constant and influences a person's fertility.
