{"id":38,"date":"2020-04-08T14:57:52","date_gmt":"2020-04-08T14:57:52","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=38"},"modified":"2023-08-16T10:42:14","modified_gmt":"2023-08-16T10:42:14","slug":"calcium","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/calcium\/","title":{"rendered":"Calcium (Ca)"},"content":{"rendered":"\n

Calcium is a chemical element with an atomic number of 20 in the periodic table of elements. It\u2019s the fifth most plentiful metal found in Earth\u2019s crust and the most abundant mineral in the human body.<\/span><\/p>\n\n\n\n

Being a member of the alkali earth metals<\/a> family of periodic table elements, this chemical substance has two valence electrons. In this way, calcium easily forms numerous compounds.<\/span><\/p>\n\n\n\n

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Chemical and Physical Properties of Calcium<\/span><\/h3>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
The symbol in the periodic table of elements<\/td>Ca<\/td><\/tr>
Atomic number<\/td>20<\/td><\/tr>
Atomic weight (mass)<\/td>40.078 g.mol-1<\/td><\/tr>
Group number<\/td>Group 2 (IIa)<\/td><\/tr>
Period<\/td>4<\/td><\/tr>
Color<\/td>A dull gray, silver<\/a> metal with a pale yellow tint<\/td><\/tr>
Physical state<\/td>A lightweight metal at room temperature<\/td><\/tr>
Half-life<\/td>From a few days to 100,000 years<\/td><\/tr>
Electronegativity according to Pauling<\/td>1<\/td><\/tr>
Density<\/td>1.54<\/td><\/tr>
Melting point<\/td>842 \u00b0C (1,548 \u00b0F)<\/td><\/tr>
Boiling point<\/td>1,484 \u00b0C (2,703 \u00b0F)<\/td><\/tr>
Van der Waals radius<\/td>0.197 nm<\/td><\/tr>
Ionic radius<\/td>0.099 nm<\/td><\/tr>
Isotopes<\/td>26<\/td><\/tr>
Most characteristic isotope<\/td>Calcium-40<\/td><\/tr>
Electronic shell<\/td>[Ar] 4s2<\/td><\/tr>
The energy of the first ionization<\/td>589.6 kJ.mol-1<\/td><\/tr>
The energy of the second ionization<\/td>1145 kJ.mol-1<\/td><\/tr>
Discovery date<\/td>In 1808 by Sir Humphry Davy<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

This alkaline earth metal is labeled with the symbol Ca in the periodic table of elements. It\u2019s a trimorphic element, meaning it occurs in three distinct forms. It has 20 protons and 20 electrons, an atomic weight of 40.078 g.mol -1, electron configuration <\/span>1<\/span>s<\/span><\/i>2<\/span>2<\/span>s<\/span><\/i>2<\/span>2<\/span>p<\/span><\/i>6<\/span>3<\/span>s<\/span><\/i>2<\/span>3<\/span>p<\/span><\/i>6<\/span>4<\/span>s<\/span><\/i>2<\/span>, and oxidation state of +2. <\/span><\/p>\n\n\n\n

Calcium shares both the chemical and physical properties with the members of the group it belongs to – the elements strontium<\/a>, barium<\/a>, and radium<\/a>. With a cubic crystal structure, its boiling point occurs at 1,484 \u00b0C (2,703 \u00b0F), while the melting point of calcium is achieved at 842 \u00b0C (1,548 \u00b0F). <\/span><\/p>\n\n\n\n

Furthermore, the fact sheet of this member of the alkali earth metals family of elements in the periodic table also contains the following values: an electronegativity of 1.0 according to Pauling, and an atomic radius according to van der Waals is 0.197 nm. <\/span><\/p>\n\n\n\n

Calcium is highly reactive with water – it occurs as Ca2+ (aq), CaOH+ (aq), Ca(OH)2 (aq), or as CaSO4. Due to its buffering qualities, calcium is often used as a pH stabilizer in drinking water which makes it more tasteful. <\/span><\/p>\n\n\n\n

Water-solving calcium hydroxide is formed with the following reaction:<\/span><\/p>\n\n\n\n

Ca (s) + 2H2O (g) -> Ca(OH)2 (aq) + H2 (g)<\/em><\/strong><\/span><\/p>\n\n\n\n

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How Was Calcium Discovered?<\/span><\/h2>\n\n\n\n

The <\/span>Egyptian blue<\/span><\/i>, or calcium copper <\/a>silicate (CaCuSi4O10) also known as cuprorivaite, has been used since ancient times (approximately 5000 years ago) as a coloring pigment with vivid blue color. The Latin name for this first synthetically produced pigment was \u2018caeruleum\u2019, meaning \u2018color of the sky\u2019. <\/span><\/p>\n\n\n\n

Since the Egyptians considered the blue color as the color of the heavens and the Universe, they worshipped the <\/span>lapis lazuli<\/span><\/i> – a naturally found mineral with an intensive blue color. However, this semi-precious stone was perceived as a luxury item even in ancient times. Therefore, the people from this ancient civilization succeeded in manufacturing its alternative, called accordingly – the \u2018Egyptian blue\u2019. <\/span><\/p>\n\n\n\n

The first evidence of this form of calcium dates from the time of the last pharaoh of the First Egyptian Dynasty, Sekhen. Egyptians were mainly using the calcium copper silicate to make the ceramic glaze known as the \u2018Egyptian faience\u2019. <\/span><\/p>\n\n\n\n

Due to its beautiful color and properties that the ancient Egyptians assigned to this gemstone, it quickly found its way among the people of the Meditteranean. The monumental Parthenon in Athens and some paintings found in Pompeii evidence of the use of this mineral by the ancient Greeks and Romans, respectively.   <\/span><\/p>\n\n\n\n

The ancient civilizations have also used calcium oxide (CaO), i.e. the lime, as a building material. Prior to the use, they were heating the calcium compound in order to obtain mortar. <\/span><\/p>\n\n\n\n

The father of modern chemistry, Antoine-Laurent de Lavoisier (Antoine Lavoisier) regarded calcium as an unknown chemical element oxide and classified it as an earth element since he believed that it cannot be further reduced.  <\/span><\/p>\n\n\n\n

In 1808, the British chemist Sir Humphrey Davy attempted to distill mercury <\/a>from lime and a mercuric oxide compound with the method of electrolysis. The experiment he conducted resulted in a silvery metal that\u2019s softer than aluminum, which entered the periodic table of elements in the second group of alkali earth elements. It was the pure form of calcium (Ca).\u00a0<\/span><\/p>\n\n\n\n

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How Did Calcium Get Its Name?<\/span><\/h2>\n\n\n\n

The Latin word \u2018calx\u2019, denoting lime, was used to label this chemical element of the alkali earth metal family of periodic table elements.\u00a0<\/span><\/p>\n\n\n\n

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Where Can You Find Calcium?<\/span><\/h2>\n\n\n\n

Accumulated in a quantity of 3.64 percent in the Earth\u2019s crust, calcium can be found as a calcium carbonate compound (CO<\/span>3<\/span>) that occurs in limestone (CaCo<\/span>3<\/span>), fluorite (CaF<\/span>2<\/span>), chalk, eggshells, gypsum (CaSO<\/span>4<\/span>\u00b72H<\/span>2<\/span>O), pearls, apatite [Ca\u2085(PO\u2084)\u2083], the shells of the marine animals, corals, stalactites, stalagmites, marble, and dolomite. <\/span><\/p>\n\n\n\n

Calcium also comprises about 8 percent of the Moon\u2019s crust, and naturally occurs in the waters by dissolving from calcite rocks. Despite the fact that this chemical substance cannot be easily found in its elemental form, it does create an abundance of compounds that can be traced in rock-forming minerals such as feldspars and zeolites.<\/span><\/p>\n\n\n\n

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Calcium and Human Health <\/span><\/h2>\n\n\n\n

Calcium is one of the most important trace elements since it is the main substance of which our bones and teeth are made of. In fact, it\u2019s found in almost all life-forms on Earth. Since our skeletal system and teeth are made of over 99% of this chemical substance, calcium makes for one of the main components required for a healthy bone structure and strong teeth in the form of calcium hydroxyl phosphate. <\/span><\/p>\n\n\n\n

This mineral is also very important for the proper function of the heart, muscles, and nervous system. It supports the proper functioning of the cellular mechanisms and the division of neuronal cells. In addition, this essential nutrient supports the relay of sensory information to the dedicated brain areas, the secretion of hormones, etc.\u00a0<\/span><\/p>\n\n\n\n

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Which Foods Are Rich in Calcium??<\/span><\/h3>\n\n\n\n

Calcium-rich foods, such as dairy foods (cheeses, milk drinks, milk products) and broccoli, are recommended to be included in the daily diet for healthier teeth and bones, as well as for the overall wellbeing. Calcium is especially important for children, pregnant women, vegans, as well as older people, due to the increased or decreased calcium absorption, respectively. <\/span><\/p>\n\n\n\n

Dairy products, salmon, kale, Chinese cabbage, bok choy, collard greens, cheddar cheese, cottage cheese, fortified milk, green leafy vegetables, nuts, etc, are some of the best food sources for calcium. It\u2019s important to note that all foods differ in their calcium content. <\/span><\/p>\n\n\n\n

The following tabular representation of recommended daily allowance (RDA) of calcium and calcium content in food has been issued by the NIH – National Institutes of Health, Office of Dietary Supplements, provided by the Dietary Reference Intakes (DRIs), and developed by the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies (formerly National Academy of Sciences):<\/span><\/i>  <\/span><\/p>\n\n\n\n

Food<\/b><\/td>Milligrams (mg) per serving<\/b><\/td><\/tr>
Yogurt, plain, low fat<\/span><\/td>415<\/span><\/td><\/tr>
Orange juice, calcium-fortified<\/span><\/td>349<\/span><\/td><\/tr>
Mozzarella, part-skim<\/span><\/td>333<\/span><\/td><\/tr>
Sardines, canned in oil, with bones<\/span><\/td>325<\/span><\/td><\/tr>
Cheddar cheese<\/span><\/td>307<\/span><\/td><\/tr>
Milk, nonfat<\/span><\/td>299<\/span><\/td><\/tr>
Soymilk, calcium-fortified<\/span><\/td>299<\/span><\/td><\/tr>
Milk, reduced-fat (2% milk fat)<\/span><\/td>293<\/span><\/td><\/tr>
Yogurt, fruit, low fat<\/span><\/td>258<\/span><\/td><\/tr>
Salmon, pink, canned, solids with bone<\/span><\/td>181<\/span><\/td><\/tr>
Cottage cheese, 1% milk fat<\/span><\/td>138<\/span><\/td><\/tr>
Breakfast cereals, fortified with 10% of the DV for calcium<\/span><\/td>130<\/span><\/td><\/tr>
Turnip greens, fresh, boiled<\/span><\/td>99<\/span><\/td><\/tr>
Kale, fresh, cooked<\/span><\/td>94<\/span><\/td><\/tr>
Ice cream, vanilla<\/span><\/td>84<\/span><\/td><\/tr>
Chia seeds<\/span><\/td>76<\/span><\/td><\/tr>
Bread, white<\/span><\/td>73<\/span><\/td><\/tr>
Bread, whole-wheat<\/span><\/td>30<\/span><\/td><\/tr>
Broccoli, raw<\/span><\/td>21<\/span><\/td><\/tr>
Cream cheese, regular<\/span><\/td>14<\/span><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Source: <\/span>https:\/\/ods.od.nih.gov\/factsheets\/Calcium-HealthProfessional\/<\/span><\/a><\/p>\n\n\n\n

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What Happens When the Calcium Levels in Our Body Are Low?<\/span><\/h3>\n\n\n\n

When calcium levels in the body are below normal, various health issues may appear, such as hypocalcemia, osteoporosis, rickets, osteomalacia, or hypoparathyroidism.\u00a0<\/span><\/p>\n\n\n\n

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Hypocalcemia<\/span><\/h4>\n\n\n\n

Due to calcium deficiency, also known as Hypocalcemia, our body may lose its strength, the muscles start to cramp, and tingling in the limbs may occur. In such cases, calcium supplements that increase the amount of calcium in the body are administered in therapies when there\u2019s not enough calcium for strong bones and proper cellular function.<\/span><\/p>\n\n\n\n

In order for the calcium to be easily absorbed in the human body, it needs the help of vitamin D. This vitamin can be produced in the body by a healthy exposure to sunlight or can be gained from supplements or vitamin D rich foods such as fish oil, orange juice, and other fruit juices, salmon, cheese, eggs, pork chops, and mushrooms. <\/span><\/p>\n\n\n\n

Vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) are the two most important supplement forms of this vitamin that are needed for improved bone health.\u00a0<\/span><\/p>\n\n\n\n

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Osteoporosis<\/span><\/h4>\n\n\n\n

Low levels or lack of calcium can trigger demineralization of bones. The bone density is lost, and as a result, osteoporosis may occur. Namely, osteoporosis is a medical condition characterized by the loss of bone density due to calcium deficiency. <\/span><\/p>\n\n\n\n

Since calcium is the main mineral involved in the formation of the skeletal structure of the body, osteoporosis occurs as a result of the disbalance between the formation of the bone and its resorption – risk factors that ultimately lead to bone loss or easily broken bones.<\/span><\/p>\n\n\n\n

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What Are the Symptoms of Osteoporosis?<\/span><\/h4>\n\n\n\n

While the symptoms may not be easily detectable for many years, the conditions that are experienced by the affected individuals include:<\/span><\/p>\n\n\n\n