Which zinc ion is most likely to form

According to the Aufbau process, the electrons fill the 4 s sublevel before beginning to fill the 3 d sublevel. However, the outermost s electrons are always the first to be removed in the process of forming transition metal cations.

This is the case for iron above. A half-filled d sublevel d 5 is particularly stable, which is the result of an iron atom losing a third electron.

Iron II sulfate, FeSO 4 , has been known since ancient times as green vitriol and was used for centuries in the manufacture of inks. Some transition metals that have relatively few d electrons may attain a noble-gas electron configuration.

Scandium is an example. Zinc tends to form bonds with a greater degree of covalency and it forms much more stable complexes with N- and S- donors. Complexes of zinc are mostly 4- or 6- coordinate although 5-coordinate complexes are known. It is also used to make other chemicals. Zinc methyl Zn CH3 2 is used in a number of organic syntheses.

Zinc sulfide ZnS is used in luminescent pigments such as on the hands of clocks, X-ray and television screens, and luminous paints. Crystals of ZnS are used in lasers that operate in the mid-infrared part of the spectrum. Zinc sulphate is a chemical in dyes and pigments. Zinc pyrithione is used in antifouling paints.

It is a moderately reactive metal and strong reducing agent. The surface of the pure metal tarnishes quickly, eventually forming a protective passivating layer of the basic zinc carbonate, Zn5 OH 6CO3, by reaction with atmospheric carbon dioxide. This layer helps prevent further reaction with air and water. The metal also has a flexible coordination geometry, which allows proteins using it to rapidly shift conformations to perform biological reactions. Two examples of zinc-containing enzymes are carbonic anhydrase and carboxypeptidase, which are vital to the processes of carbon dioxide CO2 regulation and digestion of proteins, respectively.

Physiologically, it exists as an ion in the body. It is estimated that of the hundreds of thousands of proteins in the human body contain zinc prosthetic groups. In addition, there are over a dozen types of cells in the human body that secrete zinc ions, and the roles of these secreted zinc signals in medicine and health are now being actively studied. Intriguingly, brain cells in the mammalian forebrain are one type of cell that secretes zinc, along with its other neuronal messenger substances.

Cells in the salivary gland, prostate, immune system and intestine are other types that secrete zinc. Obtaining a sufficient zinc intake during pregnancy and in young children is a problem, especially among those who cannot afford a good and varied diet. Brain development is stunted by zinc deficiency in utero and in youth. Zinc is an activator of certain enzymes, such as carbonic anhydrase. Carbonic anhydrase is important in the transport of carbon dioxide in vertebrate blood.

Even though zinc is an essential requirement for a healthy body, too much zinc can be harmful. Excessive absorption of zinc can also suppress copper and iron absorption. Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children it causes growth retardation, delayed sexual maturation, infection susceptibility, and diarrhea, contributing to the death of about , children worldwide per year.

Enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc can cause ataxia, lethargy and copper deficiency. Zinc is found in nearly specific enzymes other sources say , serves as structural ions in transcription factors and is stored and transferred in metallothioneins.

It is "typically the second most abundant transition metal in organisms" after iron and it is the only metal which appears in all enzyme classes. This produces zinc sulfide, together with large amounts of hot gas, heat, and light. Zinc sheet metal is used to make zinc bars. It is somewhat less dense than iron and has a hexagonal crystal structure. Synonym Source 30Zn. Belongs to the class of inorganic compounds known as homogeneous transition metal compounds. These are inorganic compounds containing only metal atoms,with the largest atom being a transition metal atom.

Inorganic compounds. Homogeneous metal compounds. Homogeneous transition metal compounds. Property Value Reference Physical state Solid. Descriptor ID Definition Reference angiotensin converting enzyme inhibitor. An EC 3. An agent capable of relieving pain without the loss of consciousness or without producing anaesthesia.

In addition, analgesic is a role played by a compound which is exhibited by a capability to cause a reduction of pain symptoms. An agent and endogenous substances that antagonize or inhibit the development of new blood vessels.

A substance that kills or slows the growth of microorganisms, including bacteria, viruses, fungi and protozoans. In the Earth's crust, it is found at a concentration of ppm mostly in the form water and of organic compounds , making it the 10th most abundant element. Of course, there's also "dark matter" and "dark energy" to worry about, but that's another story.

Hydrogen, helium, and trace amounts of lithium were produced at the beginning of the Universe in the Big Bang, and became concentrated into stars by the force of gravity. The fusion of hydrogen and its isotopes see below also powers the hydrogen bomb, which contains lithium deuteride LiD and tritium; the explosion of a fission-powered bomb produces neutrons which initiate fusion of the deuterium with the tritium, releasing vast amounts of energy.

Research into achieving controlled nuclear fusion to generate electricity is being conducted, but the extremely high temperatures that are necessary to initiate the fusion reactions present a major challenge to physicists. Hydrogen typically does not form cations, but instead forms compounds through covalent bonding.

Hydrogen can form bonds to many other elements, such as nitrogen NH 3 and its derivatives , oxygen H 2 O and sulfur H 2 S , the halogens HX , and carbon, where it is found in millions of different hydrocarbons and other organic molecules almost all organic molecules contain at least some hydrogen atoms.

Hydrogen can also bond to metal atoms, such as lithium LiH , calcium CaH 2 , etc. In these compounds, the bonding is usually pictured as a metal cation combined with a hydride anion H -. On some periodic tables, in fact, hydrogen is placed at the top of Group 7A, since like the halogens, it can form a -1 charge. Hydrogen is also found in acids , which are molecules containing easily-removed hydrogen atoms, usually connected to oxygen, nitrogen, or a halogen.

This is a greatly oversimplified explanation of acid-base chemistry. Hydrogen was discovered by the English chemist Henry Cavendish in ; hydrogen had been observed before, but Cavendish was the first to recognize not only that it was an element, but that it burned to form water, which also provided conclusive proof that water was not itself an element. The name "hydrogen" was derived by the French chemist Antoine Lavoisier from the Greek words hydro "water" and genes "forming".

There are three isotopes of hydrogen. Hydrogen-1, or protium , contains one proton in its nucleus, and is by far the most common form of hydrogen Hydrogen-2, or deuterium , contains one proton and one neutron in its nucleus, and comprises the remaining 0. Hydrogen-3, or tritium , contains one proton and two neutrons, and is only found in trace amounts; it is produced by the interaction of cosmic rays on gases in the upper atmosphere, and in nuclear explosions, but since it has a half life of only Heavy water is water made from two atoms of deuterium and one atom of oxygen.

This form of water is literally heavier than "ordinary" water, since an atom of deuterium is twice as heavy as an atom of "regular" hydrogen. H 2 O has a molar mass of Ordinary water contains about 1 molecule of D 2 O for every molecules of H 2 O. The electrolysis of water concentrates D 2 O in the solution, since the lighter isotope evaporates from the solution slightly faster.

Successive electrolysis experiments allow pure heavy water to be produced, but it takes about , gallons of water to produce 1 gallon of heavy water by this method. Heavy water is used as a moderator in nuclear reactions: it slows down fast-moving neutrons, allowing them to be captured more easily by other nuclei.

The generation of heavy water was important during the research on nuclear fission that went into the Manhattan Project during World War II. For a typical person, a fatal dose would require drinking nothing but heavy water for 10 to 14 days, so it's pretty doubtful that heavy water poisoning will be featured on CSI anytime soon.

Most hydrogen is prepared industrially be reacting coal or hydrocarbons with steam at high temperatures to produce carbon monoxide and hydrogen gas a mixture of carbon monoxide and hydrogen is called synthesis gas , and can be used in manufacturing methanol.

On smaller scales it can be produced by the reaction of active metals such as zinc, calcium, etc. Hydrogen gas is combined with nitrogen in the Haber process to synthesize ammonia NH 3 , which is widely used in fertilizers. It is also used in the manufacture of hydrogenated vegetable oils; in this reaction, hydrogen atoms add to the carbon-carbon double bonds in the vegetable oils double-bonded carbons bond to fewer hydrogen atoms than single-bonded carbons — i.

Another use for hydrogen is in rocket fuels: the Saturn V rockets that launched the Apollo lunar missions used , gallons of kerosene and , gallons of liquid oxygen in its first stage S-IC , , gallons of liquid hydrogen and 83, gallons of liquid oxygen in its second stage S-II , and 69, gallons of liquid hydrogen and 20, gallons of liquid oxygen in its third S-IVB stage; the Space Shuttle main engines use , gallons of liquid hydrogen and , gallons of liquid oxygen.

Hydrogen is lighter than air, and was used in balloons and dirigibles also known as airships or zeppelins. Dirigibles were used in city-to-city air travel in the early s, and in trans-Atlantic crossings in the s and s.

During World War I, German zeppelins were used in bombing runs over England, since they could fly higher than the British planes. On May 6, , the German dirigible Hindenburg caught fire as it came in for a landing at Lakehurst Naval Air Station in New Jersey; 35 people out of the 97 aboard and one person on the ground were killed. The exact cause of the fire is still the subject of speculation, but the disaster signaled the beginning of the end for airship travel.

Modern "blimps" use helium to provide lift, which avoids the problem of hydrogen's flammability. Molecules which contain hydrogen bonded to nitrogen, oxygen, or fluorine can attract one another through the formation of hydrogen bonds. Hydrogen bonds are a particularly strong form of dipole-dipole forces , which arise because of the unequal sharing of electrons in some covalent bonds.

If one atom in a covalent bond is more electronegative than the other, it "pulls" harder on the electrons that the two atoms share, giving the more electronegative atom a partial negative charge, and the less electronegative atom a partial positive charge.

The partially negative atom on one molecule attracts the partially positive atom on a neighboring molecule, causing the two molecules to be more attracted to each other than two nonpolar molecules which have no electronegativity differences between their bonded atoms would be.

Molecules that interact by these dipole-dipole forces tend to have higher boiling points than nonpolar molecules, because higher temperatures are necessary to overcome the attractive forces between the molecules and separate the molecules into the gas phase.

In the case of O—H, N—H, and F—H bonds, the electronegativity differences are particularly large because fluorine, oxygen, and nitrogen are the most strongly electronegative elements. The attractive forces between molecules containing these bonds are particularly strong, and are given the name hydrogen bonds.

Hydrogen bonds are not as strong as covalent bonds, but they greatly influence the physical properties of many substances. In particular, hydrogen bonds are responsible for the fact that water is a liquid at temperatures at which molecules of similar molecular mass are gases. For instance, hydrogen sulfide, H 2 S, which weighs Ice floats on liquid water because the hydrogen bonds hold the molecules into a more open, hexagonal array, causing the solid form to be less dense than the liquid form.

In living systems, hydrogen bonding plays a crucial role in many biochemical process, from the coiling of proteins into complex three-dimensional forms to the structure of the DNA double helix, in which the two strands of DNA are held together by the hydrogen bonding between their nucleic acids components.

In this technique, a sample is placed in a powerful magnetic field usually produced by a superconducting magnet — see the section on Helium , which causes the hydrogen atoms in the sample to resonate between two different magnetic energy levels; pulsing the sample with a burst of radiofrequency radiation typically between to MHz causes the hydrogen atoms to absorb some of this radiation, producing a readout called an "NMR spectrum" which can be used to deduce a great deal of structural information about organic molecules.

Since almost all organic molecules contain hydrogen atoms, this technique is widely used by organic chemists to probe molecular structure; it can also be used to determine a great deal of information about extremely complex molecules such as proteins and DNA. The technique is nondestructive, and only requires small amounts of sample.