![]() For example, when it goes into muscle cells, it makes them contract (shorten so the muscle pulls.) When it goes into nerve cells, it triggers electrical impulses that send a message. Once in the cell calcium ions activates many proteins to do specific things. The cell is told to act and it opens the channels. These are openings where calcium ions can enter the cell. Many cells have calcium channels on their surface. Calcium carbonate, also known as calcite, is the most common calcium mineral.Ĭalcium in cells Occurrence In the ground CalciteĬalcium is not found as a metal in the ground it is too reactive. However, along with calcium-46, it is theoretically unstable but with a half-life so long it has never been observed to decay. Since it decays to potassium-41, it is a critical indicator of solar system anomalies.Ĭalcium-40 is the most abundant isotope (96% of all natural calcium), since it comes from radiogenic 40K, which has a half-life of 1.25 billion years. 41Ca is made by the neutron activation of 40Ca in the upper layers of the Earth's crust and has a half-life of 102,000 years. Traces of 41Ca, 45Ca and 47Ca are made by cosmic rays striking atoms, and are called cosmogenic nuclides. Calcium oxide was used to make limelights, which have a flame heating calcium oxide and makes it glow very bright.Ĭalcium has 6 naturally occurring isotopes ( 40Ca, 42Ca, 43Ca, 44Ca, 46Ca and 48Ca), of which 48Ca is very slightly radioactive with a half-life about 6.4×10 19 years. They are unreactive as far as calcium ions go. They are needed in the human body, actually. It can react with halogens to make calcium halides like calcium chloride with chlorine.Ĭalcium compounds Ĭalcium forms chemical compounds in the +2 oxidation state. It also makes calcium nitride when heated. It burns when powdered to make a reddish flame. If a little acid is added to calcium hydroxide, it dissolves it, making the calcium react very fast. When it is in a chunk, it starts reacting slowly because calcium hydroxide makes a coating that does not dissolve on the calcium. It reacts with water very fast when it is powdered. It reacts with water to produce hydrogen and calcium hydroxide. It does not conduct electricity as well as copper, but is much lighter in weight.Ĭhemical properties Calcium metal burning Its melting point is hotter than most other reactive metals. Properties Physical properties Ĭalcium is a soft white-gray metal. Its mass number is about 40.08.Ĭalcium is very important in the human body, for making bones and for other purposes. ![]() The most common isotopes are Ca-40 and Ca-44. (The atomic number says where Calcium sits in the periodic table.) It has 20 protons and 20 electrons (if is an atom, see ion). Its symbol on the periodic table (a list of all the elements) is Ca. Very pure calcium metal, not corroded Calcium metal in air, corrodedĬalcium is a chemical element.
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