Even with multiple fillings, the mercury levels in the patients remain far below the lowest levels associated with harm. Clinical studies have found no link between dental amalgams and health problems.
Health issues may not be the same in cases of children under six or pregnant women. The only health consideration noted is that some people are allergic to the amalgam or one of its components. Group 13 contains the metalloid boron and the metals aluminum, gallium, indium, and thallium.
The lightest element, boron, is semiconducting, and its binary compounds tend to be covalent and not ionic. The remaining elements of the group are metals, but their oxides and hydroxides change characters. The oxides and hydroxides of aluminum and gallium exhibit both acidic and basic behaviors.
A substance, such as these two, that will react with both acids and bases is amphoteric. This characteristic illustrates the combination of nonmetallic and metallic behaviors of these two elements. Indium and thallium oxides and hydroxides exhibit only basic behavior, in accordance with the clearly metallic character of these two elements. Aluminum is amphoteric because it will react with both acids and bases.
A typical reaction with an acid is:. The products of the reaction of aluminum with a base depend upon the reaction conditions, with the following being one possibility:. With both acids and bases, the reaction with aluminum generates hydrogen gas. The group 13 elements have a valence shell electron configuration of ns 2 np 1. This phenomenon, the inert pair effect, refers to the formation of a stable ion with an oxidation state two lower than expected for the group.
The pair of electrons is the valence s orbital for those elements. In general, the inert pair effect is important for the lower p -block elements. The metals of group 13 all react directly with nonmetals such as sulfur, phosphorus, and the halogens, forming binary compounds. The metals of group 13 Al, Ga, In, and Tl are all reactive. However, passivation occurs as a tough, hard, thin film of the metal oxide forms upon exposure to air.
Disruption of this film may counter the passivation, allowing the metal to react. One way to disrupt the film is to expose the passivated metal to mercury.
Some of the metal dissolves in the mercury to form an amalgam, which sheds the protective oxide layer to expose the metal to further reaction. The formation of an amalgam allows the metal to react with air and water.
Although easily oxidized, the passivation of aluminum makes it very useful as a strong, lightweight building material. Because of the formation of an amalgam, mercury is corrosive to structural materials made of aluminum.
This video demonstrates how the integrity of an aluminum beam can be destroyed by the addition of a small amount of elemental mercury. The most important uses of aluminum are in the construction and transportation industries, and in the manufacture of aluminum cans and aluminum foil. These uses depend on the lightness, toughness, and strength of the metal, as well as its resistance to corrosion.
Because aluminum is an excellent conductor of heat and resists corrosion, it is useful in the manufacture of cooking utensils. Aluminum is a very good reducing agent and may replace other reducing agents in the isolation of certain metals from their oxides. Although more expensive than reduction by carbon, aluminum is important in the isolation of Mo, W, and Cr from their oxides.
The metallic members of group 14 are tin, lead, and flerovium. Carbon is a typical nonmetal. The remaining elements of the group, silicon and germanium, are examples of semimetals or metalloids.
The stability of this oxidation state is a consequence of the inert pair effect. For example, SnCl 4 and PbCl 4 are low-boiling covalent liquids. Tin reacts readily with nonmetals and acids to form tin II compounds indicating that it is more easily oxidized than hydrogen and with nonmetals to form either tin II or tin IV compounds shown in Figure 8 , depending on the stoichiometry and reaction conditions.
Lead is less reactive. It is only slightly easier to oxidize than hydrogen, and oxidation normally requires a hot concentrated acid. Many of these elements exist as allotropes. Allotropes are two or more forms of the same element in the same physical state with different chemical and physical properties. There are two common allotropes of tin. These allotropes are grey brittle tin and white tin. As with other allotropes, the difference between these forms of tin is in the arrangement of the atoms.
White tin is stable above At low temperatures, gray tin is the more stable form. Gray tin is brittle and tends to break down to a powder. Consequently, articles made of tin will disintegrate in cold weather, particularly if the cold spell is lengthy. The change progresses slowly from the spot of origin, and the gray tin that is first formed catalyzes further change.
In a way, this effect is similar to the spread of an infection in a plant or animal body, leading people to call this process tin disease or tin pest. The principal use of tin is in the coating of steel to form tin plate-sheet iron, which constitutes the tin in tin cans. Important tin alloys are bronze Cu and Sn and solder Sn and Pb. Lead is important in the lead storage batteries in automobiles. Bismuth , the heaviest member of group 15, is a less reactive metal than the other representative metals.
This section focuses on the periodicity of the representative elements. These are the elements where the electrons are entering the s and p orbitals. The representative elements occur in groups 1, 2, and 12— These elements are representative metals, metalloids, and nonmetals. The outermost electrons of the alkaline earth metals group 2 are more difficult to remove than the outer electron of the alkali metals, leading to the group 2 metals being less reactive than those in group 1.
Aluminum, gallium, indium, and thallium group 13 are easier to oxidize than is hydrogen. The alkali metals all have a single s electron in their outermost shell.
In contrast, the alkaline earth metals have a completed s subshell in their outermost shell. In general, the alkali metals react faster and are more reactive than the corresponding alkaline earth metals in the same period. The possible ways of distinguishing between the two include infrared spectroscopy by comparison of known compounds, a flame test that gives the characteristic yellow color for sodium strontium has a red flame , or comparison of their solubilities in water.
Density determination on a solid is sometimes difficult, but there is enough difference 2. In PbCl 4 , the bonding is covalent, as evidenced by it being an unstable liquid at room temperature. Skip to content Chapter Representative Metals, Metalloids, and Nonmetals. When pressure is controlled, other pure elements may be found at room temperature. An example is the halogen element chlorine. Actively scan device characteristics for identification. Use precise geolocation data.
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Facebook Facebook Twitter Twitter. Key Takeaways: Liquid Elements Only two elements on the periodic table are elements at room temperature. They are mercury a metal and bromine a halogen. The RSC has been granted the sole and exclusive right and licence to produce, publish and further license the Images. The RSC maintains this Site for your information, education, communication, and personal entertainment. You may browse, download or print out one copy of the material displayed on the Site for your personal, non-commercial, non-public use, but you must retain all copyright and other proprietary notices contained on the materials.
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Glossary Allotropes Some elements exist in several different structural forms, called allotropes. Glossary Group A vertical column in the periodic table. Fact box. Group 15 Melting point Glossary Image explanation Murray Robertson is the artist behind the images which make up Visual Elements.
Appearance The description of the element in its natural form. Biological role The role of the element in humans, animals and plants. Natural abundance Where the element is most commonly found in nature, and how it is sourced commercially.
Uses and properties. Image explanation. The symbol is the Eye of Horus, an Ancient Egyptian symbol of protection, royal power and good health. The Ancient Egyptians used antimony sulfide as a mascara. Antimony is a semi-metal.
In its metallic form it is silvery, hard and brittle. Antimony is used in the electronics industry to make some semiconductor devices, such as infrared detectors and diodes. It is alloyed with lead or other metals to improve their hardness and strength. A lead-antimony alloy is used in batteries. Other uses of antimony alloys include type metal in printing presses , bullets and cable sheathing. Antimony compounds are used to make flame-retardant materials, paints, enamels, glass and pottery.
Biological role. Natural abundance. Antimony is not an abundant element but is found in small quantities in over mineral species. It is most often found as antimony III sulfide. It is extracted by roasting the antimony III sulfide to the oxide, and then reducing with carbon. Antimony can also be found as the native metal. Other producers are Bolivia, Russia and Tajikistan. Help text not available for this section currently. Elements and Periodic Table History. Antimony and its compounds were known to the ancients and there is a 5,year old antimony vase in the Louvre in Paris.
The black form of this pigment, which occurs naturally as the mineral stibnite, was used as mascara and known as khol. The most famous user was the temptress Jezebel whose exploits are recorded in the Bible.
Another pigment known to the Chaldean civilization, which flourished in what is now southern Iraq in the 6 th and 7 th centuries BC, was yellow lead antimonite. This was found in the glaze of ornamental bricks at Babylon and date from the time of Nebuchadnezzar — BC.
Antimony became widely used in Medieval times, mainly to harden lead for type, although some was taken medicinally as a laxative pill which could be reclaimed and re-used! Atomic data. Glossary Common oxidation states The oxidation state of an atom is a measure of the degree of oxidation of an atom. Oxidation states and isotopes. Glossary Data for this section been provided by the British Geological Survey.
Relative supply risk An integrated supply risk index from 1 very low risk to 10 very high risk. Recycling rate The percentage of a commodity which is recycled.
Substitutability The availability of suitable substitutes for a given commodity. Reserve distribution The percentage of the world reserves located in the country with the largest reserves. Political stability of top producer A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators.
Political stability of top reserve holder A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators. Supply risk. Relative supply risk 9 Crustal abundance ppm 0. Young's modulus A measure of the stiffness of a substance. Shear modulus A measure of how difficult it is to deform a material. Bulk modulus A measure of how difficult it is to compress a substance.
Vapour pressure A measure of the propensity of a substance to evaporate. Pressure and temperature data — advanced. Listen to Antimony Podcast Transcript :. You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry.
Hello, this week we meet the chemical that's maimed and murdered, but often with the best intentions. To tell the story of the element that can't quite make up its mind if it's a metal or not here's Phil Ball.
Many wars have been fought over territory, some over pride or love or money. But in the s a long and bitter war was waged over antimony.
What, you might ask, is there to fight about in this apparently unremarkable element, a soft, greyish metal that doesn't even conduct electricity well enough to qualify as a true metal? It has its uses, but they are mundane: as an alloy component of battery electrodes and of pewter, and as a flame retardant. But at the heart of the Antimony War, which raged in France and Germany throughout much of the seventeenth century, was a more unlikely use of antimony.
Some doctors of that age believed that it was a vital ingredient in medicine.
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