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Its name comes from the Ancient Greek word σίδηρος (sídēros), meaning "iron". A valuable iron ore, it consists of 48% iron and lacks sulfur and phosphorus. Zinc, magnesium, and manganese commonly substitute for the iron, resulting in the siderite-smithsonite, siderite-magnesite, and siderite-rhodochrosite solid solution series. [3]
Calcium carbonate is used in the production of calcium oxide as well as toothpaste and has seen a resurgence as a food preservative and color retainer, when used in or with products such as organic apples. [58] Calcium carbonate is used therapeutically as phosphate binder in patients on maintenance haemodialysis. It is the most common form of ...
Common side effects include constipation and nausea. [1] When taken by mouth high blood calcium is uncommon. [1] Calcium supplements, unlike calcium from dietary sources, appear to increase the risk of kidney stones. [1] Adults generally require about a gram of calcium a day. [1] Calcium is particularly important for bones, muscles, and nerves. [1]
Substance Formula 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C 60 °C 70 °C 80 °C 90 °C 100 °C Barium acetate: Ba(C 2 H 3 O 2) 2: 58.8: 62: 72: 75: 78.5: 77: 75
The Na 2 S is then treated with calcium carbonate to give sodium carbonate, a commodity chemical. Recently, development of the 'MagSonic' carbothermic magnesium process has restarted interest in its chemistry: [4] MgO + C ↔ Mg + CO. The reaction is readily reversible from its product vapors, and requires rapid cooling to prevent back-reaction.
Iron(II) carbonate, or ferrous carbonate, is a chemical compound with formula FeCO 3 , that occurs naturally as the mineral siderite . At ordinary ambient temperatures, it is a green-brown ionic solid consisting of iron(II) cations Fe 2+
The US Institute of Medicine (IOM) established Recommended Dietary Allowances (RDAs) for calcium in 1997 and updated those values in 2011. [6] See table. The European Food Safety Authority (EFSA) uses the term Population Reference Intake (PRIs) instead of RDAs and sets slightly different numbers: ages 4–10 800 mg, ages 11–17 1150 mg, ages 18–24 1000 mg, and >25 years 950 mg. [10]
Calcium regulation in the human body. [6]The plasma ionized calcium concentration is regulated within narrow limits (1.3–1.5 mmol/L). This is achieved by both the parafollicular cells of the thyroid gland, and the parathyroid glands constantly sensing (i.e. measuring) the concentration of calcium ions in the blood flowing through them.