Period 3 element
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Part of a series on the |
Periodic table |
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A period 3 element is one of the
Atomic structure
In a
Elements
Element | # | Symbol | Block | Electron configuration |
---|---|---|---|---|
Sodium | 11 | Na | s-block |
[Ne] 3s1 |
Magnesium | 12 | Mg | s-block |
[Ne] 3s2 |
Aluminium | 13 | Al | p-block |
[Ne] 3s2 3p1 |
Silicon | 14 | Si | p-block |
[Ne] 3s2 3p2 |
Phosphorus | 15 | P | p-block |
[Ne] 3s2 3p3 |
Sulfur | 16 | S | p-block |
[Ne] 3s2 3p4 |
Chlorine | 17 | Cl | p-block |
[Ne] 3s2 3p5 |
Argon | 18 | Ar | p-block |
[Ne] 3s2 3p6 |
Sodium
Sodium (symbol Na) is a soft, silvery-white, highly reactive metal and is a member of the
Many sodium compounds are useful, such as sodium hydroxide (lye) for soapmaking, and sodium chloride for use as a deicing agent and a nutrient. The same ion is also a component of many minerals, such as sodium nitrate.
The free metal, elemental sodium, does not occur in nature but must be prepared from sodium compounds. Elemental sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide.
Magnesium
Magnesium (symbol Mg) is an alkaline earth metal and has common oxidation number +2. It is the eighth most abundant element in the Earth's crust[2] and the ninth in the known universe as a whole.[3][4] Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle. It is relatively abundant because it is easily built up in supernova stars by sequential additions of three helium nuclei to carbon (which in turn is made from three helium nuclei). Due to the magnesium ion's high solubility in water, it is the third most abundant element dissolved in seawater.[5]
The free element (metal) is not found naturally on Earth, as it is highly reactive (though once produced, it is coated in a thin layer of oxide [see passivation], which partly masks this reactivity). The free metal burns with a characteristic brilliant white light, making it a useful ingredient in flares. The metal is now mainly obtained by electrolysis of magnesium salts obtained from brine. Commercially, the chief use for the metal is as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium". Since magnesium is less dense than aluminium, these alloys are prized for their relative lightness and strength.
Magnesium ions are sour to the taste, and in low concentrations help to impart a natural tartness to fresh mineral waters.
Aluminium
Aluminium (symbol Al) or aluminum (
Aluminium is remarkable for the metal's low density and for its ability to resist corrosion due to the phenomenon of passivation. Structural components made from aluminium and its alloys are vital to the aerospace industry and are important in other areas of transportation and structural materials. The most useful compounds of aluminium, at least on a weight basis, are the oxides and sulfates.
Silicon
Silicon (symbol Si) is a
Silicon is the eighth most
Most silicon is used commercially without being separated, and indeed often with little processing of compounds from nature. These include direct industrial building use of
Elemental silicon also has a large impact on the modern world economy. Although most free silicon is used in the steel refining, aluminum-casting, and fine chemical industries (often to make
Phosphorus
Phosphorus (symbol P) is a
The first form of elemental phosphorus to be produced (white phosphorus, in 1669) emits a faint glow upon exposure to oxygen – hence its name given from Greek mythology, Φωσφόρος meaning "light-bearer" (Latin: Lucifer), referring to the "Morning Star", the planet Venus. Although the term "phosphorescence", meaning glow after illumination, derives from this property of phosphorus, the glow of phosphorus originates from oxidation of the white (but not red) phosphorus and should be called chemiluminescence. It is also the lightest element to easily produce stable exceptions to the octet rule.
The vast majority of phosphorus compounds are consumed as fertilizers. Other applications include the role of
Sulfur
Sulfur (symbol S) is an
.In nature, sulfur can be found as the pure element and as sulfide and sulfate minerals. Elemental sulfur crystals are commonly sought after by mineral collectors for their brightly colored polyhedron shapes. Being abundant in native form, sulfur was known in ancient times, mentioned for its uses in ancient Greece, China and Egypt. Sulfur fumes were used as fumigants, and sulfur-containing medicinal mixtures were used as balms and antiparasitics. Sulfur is referenced in the Bible as brimstone in English, with this name still used in several nonscientific terms.[10] Sulfur was considered important enough to receive its own alchemical symbol. It was needed to make the best quality of black gunpowder, and the bright yellow powder was hypothesized by alchemists to contain some of the properties of gold, which they sought to synthesize from it. In 1777, Antoine Lavoisier helped convince the scientific community that sulfur was a basic element, rather than a compound.
Elemental sulfur was once extracted from salt domes, where it sometimes occurs in nearly pure form, but this method has been obsolete since the late 20th century. Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum. The element's commercial uses are primarily in fertilizers, because of the relatively high requirement of plants for it, and in the manufacture of sulfuric acid, a primary industrial chemical. Other well-known uses for the element are in matches, insecticides and fungicides. Many sulfur compounds are odiferous, and the smell of odorized natural gas, skunk scent, grapefruit, and garlic is due to sulfur compounds. Hydrogen sulfide produced by living organisms imparts the characteristic odor to rotting eggs and other biological processes.
Chlorine
Chlorine (symbol Cl) is the second-lightest
The most common compound of chlorine, sodium chloride (
Chlorine is a component of many other compounds. It is the
Argon
Argon (symbol Ar) is the third element in group 18, the
The name "argon" is derived from the Greek neuter adjective ἀργόν, meaning "lazy" or "the inactive one", as the element undergoes almost no chemical reactions. The complete octet (eight electrons) in the outer atomic shell makes argon stable and resistant to bonding with other elements. Its triple point temperature of 83.8058 K is a defining fixed point in the International Temperature Scale of 1990.
Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding gas in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive: for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. Argon gas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon makes a distinctive blue–green gas laser.
Biological roles
Sodium is an
Magnesium is the eleventh most abundant element by mass in the
Despite its prevalence in the environment, aluminium salts are not known to be used by any form of life. In keeping with its pervasiveness, it is well tolerated by plants and animals.[12] Because of their prevalence, potential beneficial (or otherwise) biological roles of aluminium compounds are of continuing interest.
Silicon is an essential element in biology, although only tiny traces of it appear to be required by animals,
Phosphorus is essential for life. As phosphate, it is a component of DNA, RNA, ATP, and also the phospholipids that form all cell membranes. Demonstrating the link between phosphorus and life, elemental phosphorus was historically first isolated from human urine, and bone ash was an important early phosphate source. Phosphate minerals are fossils. Low phosphate levels are an important limit to growth in some aquatic systems. Today, the most important commercial use of phosphorus-based chemicals is the production of fertilizers, to replace the phosphorus that plants remove from the soil.
Sulfur is an essential element for all life, and is widely used in biochemical processes. In metabolic reactions, sulfur compounds serve as both fuels and respiratory (oxygen-replacing) materials for simple organisms. Sulfur in organic form is present in the vitamins biotin and thiamine, the latter being named for the Greek word for sulfur. Sulfur is an important part of many enzymes and in antioxidant molecules like glutathione and thioredoxin. Organically bonded sulfur is a component of all proteins, as the amino acids cysteine and methionine. Disulfide bonds are largely responsible for the mechanical strength and insolubility of the protein keratin, found in outer skin, hair, and feathers, and the element contributes to their pungent odor when burned.
Elemental chlorine is extremely dangerous and poisonous for all lifeforms, and is used as a pulmonary agent in chemical warfare; however, chlorine is necessary to most forms of life, including humans, in the form of chloride ions.
Argon has no biological role. Like any gas besides oxygen, argon is an
Table of elements
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | |
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Group → | ||||||||||||||||||
↓ Period | ||||||||||||||||||
3 | ||||||||||||||||||
Notes
References
- ^ Period 3 Element Archived 2012-07-29 at the Wayback Machine from Scienceaid.co.uk
- ^ Railsback, L. Bruce. "Abundance and form of the most abundant elements in Earth's continental crust" (PDF). Some Fundamentals of Mineralogy and Geochemistry. Archived (PDF) from the original on 2011-09-27. Retrieved 2008-02-15.
- ISBN 978-0-13-175553-6.
- ISBN 0-7566-1321-3. Archived from the originalon 2010-02-10.
- ^ Anthoni, J Floor (2006). "The chemical composition of seawater".
- ISBN 0-06-042995-X, p. 28
- ^ Shakhashiri, Bassam Z. "Chemical of the Week: Aluminum". Science is Fun. Archived from the original on 2007-09-06. Retrieved 2007-08-28.
- ^ Nave, R. Abundances of the Elements in the Earth's Crust, Georgia State University
- ISBN 0-7506-3365-4.
- ^ "Magnesium in health".
- ISBN 978-3527306732.
- PMID 6087860.