| 单词 | cation |
| 例句 | As to the forces that held the chains together, the best guess seemed to be salt bridges in which divalent cations like Mg++ held together two or more phosphate groups. Double Helix 1968-02-27T00:00:00Z He likes it for such technical aspects as a low carbon-to-nitrogen ratio, high mineral content and its high cation exchange capacity, which is a measure of the availability of nutrients to plants. Would you use human waste in your garden? 2017-08-22T04:00:00Z Such soil also increases the number of cations, the particles that transfer nutrients from soil to root. Why gardens need fertilizer — or not 2015-02-10T05:00:00Z As we spent a chilly couple of hours in the fields, he kept returning to the need to maintain proper levels of cation exchange capacity. Preparing trees to go from green pastures to the concrete jungle 2017-12-18T05:00:00Z It is a world full of shifting ions, the negatively charged particles known as cations and the positive anions, and molecular transformations, and yes, it is all as dense as a jungle thicket. Why gardens need fertilizer — or not 2015-02-10T05:00:00Z Dual-ion batteries utilize both lithium cations and counter anions simultaneously, offering a high energy density akin to traditional batteries. Making electric vehicles last 2023-11-02T04:00:00Z Salts are compounds with positively charged cations and negatively charged anions, with some of the most abundant ones being calcium, magnesium, potassium and sulfate ions. Humans are disrupting natural 'salt cycle' on a global scale, new study shows 2023-10-31T04:00:00Z "Our research in anion and cation binding can apply to not only cystic fibrosis, but a host of other channel diseases caused by defective ion channels." Synthetic molecules can 'ferry' mucus-clearing ions blocked by cystic fibrosis 2023-10-10T04:00:00Z Through advanced atomic-scale measurements and calculations, the team found that these interlayer transition metal ions act as a "cap" above or below the honeycomb structure, preventing cation migration and maintaining stability. Novel battery technology with negligible voltage decay 2023-09-28T04:00:00Z If the cations are too large to fit into the octahedral holes, the anions may adopt a more open structure, such as a simple cubic array. Chemistry 2019-02-14T00:00:00Z Such conditions are often difficult to model in the laboratory, where competence can be induced by high concentrations of divalent cations, Ca+2 or Mg+2, or electrical shock. Biology for AP Courses 2022-06-09T00:00:00Z Positive ions are formed by losing electrons and are called cations. Environmental Biology 2018-09-06T00:00:00Z Gong's lab previously developed synthetic binders for positively charged ions called cations, but chloride is a negatively charged ion, or anion. Synthetic molecules can 'ferry' mucus-clearing ions blocked by cystic fibrosis 2023-10-10T04:00:00Z All of the ions shown are cations, except for oxygen. Physical Geology 2015-01-01T00:00:00Z The larger cations can then occupy the larger cubic holes made possible by the more open spacing. Chemistry 2019-02-14T00:00:00Z The cell possesses potassium and sodium leakage channels that allow the two cations to diffuse down their concentration gradient. Biology for AP Courses 2022-06-09T00:00:00Z In general, the elements on the left side of the table lose electrons and become positive ions, called cations because they are attracted to the cathode in an electrical device. An Introduction to Geology 2017-01-01T00:00:00Z These nonspecific channels allow cations—particularly Na+, K+, and Ca2+—to cross the membrane, but exclude anions. Anatomy and Physiology 2013-06-19T00:00:00Z The tetrahedral chains continue to left and right and each is interspersed with a series of divalent cations. Physical Geology 2015-01-01T00:00:00Z When an ionic compound is composed of cations and anions of similar size in a 1:1 ratio, it typically forms a simple cubic structure. Chemistry 2019-02-14T00:00:00Z As more cations are expelled from the cell than taken in, the inside of the cell remains negatively charged relative to the extracellular fluid. Biology for AP Courses 2022-06-09T00:00:00Z The silica chains are bonded together into the crystal structures by metal cations. An Introduction to Geology 2017-01-01T00:00:00Z The ions, in this case, are cations of sodium, calcium, and potassium. Anatomy and Physiology 2013-06-19T00:00:00Z In amphibole structures, the silica tetrahedra are linked in a double chain that has an oxygen-to- silicon ratio lower than that of pyroxene, and hence still fewer cations are necessary to balance the charge. Physical Geology 2015-01-01T00:00:00Z They can be described by unit cells with either cations at the corners or anions at the corners. Chemistry 2019-02-14T00:00:00Z Because more cations are leaving the cell than are entering, this causes the interior of the cell to be negatively charged relative to the outside of the cell. Biology for AP Courses 2022-06-09T00:00:00Z Although the cations may freely substitute for each other in the crystal, they carry different ionic charges that must be balanced out in the final crystalline structure. An Introduction to Geology 2017-01-01T00:00:00Z As shown in Figure 2.8, sodium commonly donates an electron to chlorine, becoming the cation Na+. Anatomy and Physiology 2013-06-19T00:00:00Z Since the one silicon cation has a +4 charge and the two oxygen anions each have a –2 charge, the charge is balanced. Physical Geology 2015-01-01T00:00:00Z In a simple cubic array, only one cubic hole can be occupied be a cation for each anion in the array. Chemistry 2019-02-14T00:00:00Z Each day, the company goes through gallons of a disinfectant called “quat,” short for quaternary ammonium cation. Paramedics risk lives trying to save nursing home residents 2020-05-09T04:00:00Z In one reaction, water molecules ionize into positively charged H+ and OH− ions and replace mineral cations in the crystal lattice. An Introduction to Geology 2017-01-01T00:00:00Z Figure 2.15 Dissociation of Sodium Chloride in Water Notice that the crystals of sodium chloride dissociate not into molecules of NaCl, but into Na+ cations and Cl– anions, each completely surrounded by water molecules. Anatomy and Physiology 2013-06-19T00:00:00Z In all of these minerals, the cation has a +2 charge, which balances the –2 charge on the sulphate ion. Physical Geology 2015-01-01T00:00:00Z Since metals form cations, the electrode would lose mass if metal atoms in the electrode were to oxidize and go into solution. Chemistry 2019-02-14T00:00:00Z The combination prevents the structural changes driven by temperature and humidity when individual cations are used. The reality behind solar power’s next star material 2019-06-24T04:00:00Z Temperature changes affect the chemical equilibrium or cation balance in minerals. An Introduction to Geology 2017-01-01T00:00:00Z A gap junction forms channels between adjacent cardiac muscle fibers that allow the depolarizing current produced by cations to flow from one cardiac muscle cell to the next. Anatomy and Physiology 2013-06-19T00:00:00Z In olivine, it takes two divalent cations to balance the –4 charge of an isolated tetrahedron. Physical Geology 2015-01-01T00:00:00Z It is possible to consider hydrogen a group 1 element because hydrogen can lose an electron to form the cation, H+. Chemistry 2019-02-14T00:00:00Z The proteins form channels that, when activated by light, allow various cations to flow down the electrochemical gradients that form across cell membranes when there are unequal concentrations of ions inside and outside the cell. Protein structures guide the design of a much-needed tool for neuroscience 2018-09-16T04:00:00Z Ms. White said the strikes were justified, “successfully hit every target” and that the U.S. and its allies “took every measure and cation” to only hit the intended targets. Pentagon: U.S. airstrikes ‘hit the heart’ of Syria’s chemical weapons program 2018-04-14T04:00:00Z This is because the receptor is a cation channel and positively charged Na+ will rush into the cell. Anatomy and Physiology 2013-06-19T00:00:00Z The structure of pyroxene is more “permissive” than that of olivine — meaning that cations with a wider range of ionic radii can fit into it. Physical Geology 2015-01-01T00:00:00Z They readily form alloys and lose electrons to form stable cations. Chemistry 2019-02-14T00:00:00Z This breakthrough provided a snapshot of the structure of the light-activated channel and hinted at how cations are selectively conducted through it. Protein structures guide the design of a much-needed tool for neuroscience 2018-09-16T04:00:00Z Barres left medicine to do a doctorate in neurobiology at Harvard Medical School in Boston, Massachusetts, on the function and distribution of cation channels in glial cells. Ben Barres (1955–2017) 2018-01-02T05:00:00Z A positively charged ion is known as a cation. Anatomy and Physiology 2013-06-19T00:00:00Z There is even more sharing of oxygens between adjacent tetrahedra and hence fewer charge-balancing cations are needed for sheet silicate minerals. Physical Geology 2015-01-01T00:00:00Z If only half the tetrahedral holes are occupied, the numbers of anions and cations are equal. Chemistry 2019-02-14T00:00:00Z Mutational spectrum in the Ca²⁺-activated cation channel gene TRPM4 in patients with cardiac conductance disturbances. Electron cryo-microscopy structure of a human TRPM4 channel 2017-12-05T05:00:00Z Considering the lessons learned from examples such as those presented above, it should in principle be possible to design synthetic catalysts that accelerate novel reactions via stabilizing cation–π interactions in the transition state. Exploiting non-covalent π interactions for catalyst design : Nature : Nature Research 2017-03-28T04:00:00Z A cation that has donated two electrons has a net charge of +2. Anatomy and Physiology 2013-06-19T00:00:00Z In muscovite mica, the only cations present are aluminum and potassium; hence it is a non-ferromagnesian silicate mineral. Physical Geology 2015-01-01T00:00:00Z Positively charged atoms called cations are formed when an atom loses one or more electrons. Chemistry 2019-02-14T00:00:00Z This focus ignores the biological significance of cation influx itself. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z Nature provides several excellent platforms for studying cation–π interactions in both ground and transition states. Exploiting non-covalent π interactions for catalyst design : Nature : Nature Research 2017-03-28T04:00:00Z The opposite charges of cations and anions exert a moderately strong mutual attraction that keeps the atoms in close proximity forming an ionic bond. Anatomy and Physiology 2013-06-19T00:00:00Z In addition to silica tetrahedra, feldspars include the cations aluminum, potassium, sodium, and calcium in various combinations. Physical Geology 2015-01-01T00:00:00Z Note that the average masses of neutral sodium and chlorine atoms were used in this computation, rather than the masses for sodium cations and chlorine anions. Chemistry 2019-02-14T00:00:00Z The qualitative argument for considering cation influx to be the “spark of sentience”, as outlined above, is perhaps already plausible, but the quantitative details require further study. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z This new structure, however, follows on from a related study, where Leigh fashioned a pentafoil knot from five ligands and five cations. Star Of David Recreated As A Molecular Knot [Video] 2014-09-24T04:00:00Z The resting potential is the state of the membrane at a voltage of -70 mV, so the sodium cation entering the cell will cause it to become less negative. Anatomy and Physiology 2013-06-19T00:00:00Z There is no need for aluminum or any of the other cations such as sodium or potassium. Physical Geology 2015-01-01T00:00:00Z One merely needs to identify all the ions present in the solution and then consider if possible cation/anion pairing could result in an insoluble compound. Chemistry 2019-02-14T00:00:00Z I fully concur with your sentiment that the influx of cations is of vital importance in cellular excitability. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z Nearly all high–energy density cathodes for rechargeable lithium batteries are well-ordered materials in which lithium and other cations occupy distinct sites. [Report] Unlocking the Potential of Cation-Disordered Oxides for Rechargeable Lithium Batteries 2014-01-30T19:26:03.886Z The binding of acetylcholine opens ligand-gated ion channels, increasing the movement of cations across the sarcolemma. Anatomy and Physiology 2013-06-19T00:00:00Z In a solution, this movement of energy involves electrons, and ions that migrate to cation or anion electrodes. Waste CO2 Could Be Source of Extra Power 2013-08-16T14:15:00.857Z Write the complete electron configurations of these cations and anions. Chemistry 2019-02-14T00:00:00Z So it can’t just be the influx of cations that matters for consciousness, but how this inflow is patterned across time and neurons. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z Non-chemists may know what anions and cations are, but they are unlikely to remember the finer points of the Fischer–Tropsch process. Communication: Two minutes to impress 2013-02-06T18:21:43.170Z Chloride functions to balance cations in the ECF, maintaining the electrical neutrality of this fluid. Anatomy and Physiology 2013-06-19T00:00:00Z The same regions in the RNA's tend to be modified in all three primary lines of descent, but the nature of the modification tends to vary from one kingdom to another. Archaebacteria: The Third Domain of Life Missed by Biologists for Decades 2013-01-01T00:45:00.170Z When atoms of these metals form cations with a charge of 2+, where the two outer electrons are lost, they have pseudo-noble gas electron configurations. Chemistry 2019-02-14T00:00:00Z So it can’t just be that cations flowing into the cell are what matters, but the overall causal effect the inflow of charged ions has on the system. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z To counsel against wrong practices; to cation or advise; to warn against danger or an offense; - followed by of, against, or a subordinate clause. Webster's Unabridged Dictionary 2012-03-24T02:00:23.513Z Thus, cations, or positively charged ions, and anions, or negatively charged ions, are balanced in fluids. Anatomy and Physiology 2013-06-19T00:00:00Z Of course he obtained his miraculous power from Jehovah; and there must have been some communi- cation between Jehovah and the bears. The Works of Robert G. Ingersoll, Vol. 5 (of 12) Dresden Edition?Discussions 2012-02-11T03:03:49.813Z The metals form cations, the nonmetals form anions, and the resulting compounds are solids under normal conditions. Chemistry 2019-02-14T00:00:00Z So it can’t just be the inflow of cations into any neuron in any brain structure that matters for consciousness, but which neurons in which particular structures are active. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z On the theory that the phenomena are wholly due to unequal ionic velocities this result would mean that the cation like the anion moved against the conventional direction of the current. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z According to this hypothesis, the electric current is carried by the ions, the positive charges by the cations, and the negative charges by the anions. The Mechanism of Life According to Dugmore, such an act on the part of the Newfoundland Caribou plays an important role in its system of communications, not by means of sight or sound, but through the olfactory sense. The Barren Ground Caribou of Keewatin The stability of the peroxides and superoxides of the alkali metals increases as the size of the cation increases. Chemistry 2019-02-14T00:00:00Z As summarized by the foremost contributor to the science of excitable membranes, Bertil Hille, the perceptual significance of cation influx is unlikely to be strong in, for example, the giant motor axon of the squid. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z On the opposite side of the river is Athens, between which and Hudson there seems to be much communication kept up by a team-boat. Alida or, Miscellaneous Sketches of Incidents During the Late American War. Founded on Fact On the other hand, all the phosphides produce the same toxic and therapeutic effects, whatever the cation with which they are united. The Mechanism of Life Have you ever been rejected, upon appli- cation for membership in the * * *, or have you ever been expelled from the same? 2d. Ku Klux Klan Its Origin, Growth and Disbandment A salt is an ionic compound composed of cations and anions, other than hydroxide or oxide ions. Chemistry 2019-02-14T00:00:00Z During a grand mal epileptic attack the cortex is engulfed in hyper-synchronized spiking activity; that is to say, massive amounts of cations flow into cells and the patient quickly loses consciousness. Exclusive: Oliver Sacks, Antonio Damasio and Others Debate Christof Koch on the Nature of Consciousness 2015-06-17T04:00:00Z A very low island in the middle of the stream between the two places, rendered this communication somewhat difficult 197 at first, as vessels were obliged to make a great circuit. Alida or, Miscellaneous Sketches of Incidents During the Late American War. Founded on Fact Both contain iron, it is true, but neither possess the properties of the cation Fe+++, but rather those of the complex anion of which they form a part. The Mechanism of Life When a base dissolves in water the hydroxyl groups form the anions, while the metallic element forms the cations. An Elementary Study of Chemistry Mg, In, Cs, Pb, and Co would form cations because they are metals. Chemistry 2019-02-14T00:00:00Z The difference might possibly depend upon the arrangement of ions, anions and cations upon two sides of the permeable membrane of a repair cell. Northern Nut Growers Association Report of the Proceedings at the Twenty-Fourth Annual Meeting Downington, Pennsylvania, September 11 and 12, 1933 On the opposite side of the river lies Athens, between which and Hudson there seems to be much communication kept up by a team-boat. Alida or, Miscellaneous Sketches of Incidents During the Late American War. Founded on Fact Let u be the velocity of the anions, and v the velocity of the cations. The Mechanism of Life From this standpoint a metal can be defined as an element capable of forming simple cations in solution. An Elementary Study of Chemistry The height of each vertical feature or peak in a mass spectrum is proportional to the fraction of cations with the specified mass-to-charge ratio. Chemistry 2019-02-14T00:00:00Z Chastellain addressed a D�pr�cation to Louis XI. on his behalf at the time of his disgrace. Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria" A very low island in the middle of the stream between the two places rendered this communication somewhat difficult at first, as vessels were obliged to make a great circuit. Alida or, Miscellaneous Sketches of Incidents During the Late American War. Founded on Fact A similar experiment has been made with a series of cations combined with various anions. The Mechanism of Life The remainder of the molecule, which usually consists of a single atom, is the cation. An Elementary Study of Chemistry Sodium chloride is an ionic compound composed of sodium cations, Na+, and chloride anions, Cl−, combined in a 1:1 ratio. Chemistry 2019-02-14T00:00:00Z "This is the cli—cli—climax of Eas—Eas—Easter vac—c—c—c—c—cation!" Pee-Wee Harris Adrift In such a circle as that delineated, therefore, all the known anions may be grouped within, and all the cations without. Experimental Researches in Electricity, Volume 1 For example, all acids have the same cation H+. The Mechanism of Life Since all bases produce hydroxyl anions, while the cations of each are different, the properties which all bases have in common when in solution must be due to the hydroxyl ions. An Elementary Study of Chemistry As a general rule, when the representative elements form cations, they do so by the loss of the ns or np electrons that were added last in the Aufbau process. Chemistry 2019-02-14T00:00:00Z They say that in England the conversation of the very meanest is a corus- cation of impromptu epigram! The Complete Plays of Gilbert and Sullivan Thus hydrogen, oxygen, chlorine, iodine, lead, tin are ions; the three former are anions, the two metals are cations, and 1, 8, 3, 125, 104, 58, are their electro-chemical equivalents nearly. Experimental Researches in Electricity, Volume 1 He compares an electrolytic cell to a ballroom, in which are gyrating a number of dancing couples, representing the neutral molecules, and a number of isolated ladies and gentlemen representing the anions and cations respectively. The Mechanism of Life It will be noticed that in neutralization the anion of the acid and the cation of the base are not changed. An Elementary Study of Chemistry Proceeding down the groups of the periodic table, we find that cations of successive elements with the same charge generally have larger radii, corresponding to an increase in the principal quantum number, n. Chemistry 2019-02-14T00:00:00Z They owned and operated communi- cations companies, including their own geosynchronous satellite. Terminal Compromise: computer terrorism: when privacy and freedom are the victims: a novel Thus the chloride of lead is an electrolyte, and when electrolyzed evolves the two ions, chlorine and lead, the former being an anion, and the latter a cation. Experimental Researches in Electricity, Volume 1 If she had only lived, I could ave been angry and cruel towards her with some justifi- cation; but to be vindictive towards a poor dead woman recoils upon myself. Far from the Madding Crowd DEFINITION: A salt is a substance formed by the union of the anion of an acid with the cation of a base. An Elementary Study of Chemistry The first ionization energy for an element, X, is the energy required to form a cation with +1 charge: Chemistry 2019-02-14T00:00:00Z Intoxi- cation takes many forms, and this appears to be a delicious wine. Terminal Compromise: computer terrorism: when privacy and freedom are the victims: a novel But if her emotions are touched by the forcible feeding of a criminal militant suffragist, she will again go back upon that and declare that the appli- cation of force is an intolerable evil. The Unexpurgated Case Against Woman Suffrage In the words of soil science, this functioning like a storage battery for minerals is called cation exchange capacity. Organic Gardener's Composting Sometimes, as in the present case, it is the traversing of a deep cation; at others the simple crossing of a tiny brook is enough. The Land of Footprints Removing an electron from a cation is more difficult than removing an electron from a neutral atom because of the greater electrostatic attraction to the cation. Chemistry 2019-02-14T00:00:00Z Templer showed his CIA credentials to the Marine Sergeant at the security desk, and told him he needed access to a secure communi- cations channel to Washington. Terminal Compromise: computer terrorism: when privacy and freedom are the victims: a novel The terms Anion and Cation, which he applied to the constituents of the decomposed electrolyte, and the term Ion, which included both anions and cations, are still less frequently employed. Faraday as a Discoverer We now have one mole of Cs cations and one mole of F anions. Chemistry 2019-02-14T00:00:00Z After a time he led us to the edge of the hill and showed us his houses across the cation, perched on a flat about halfway up the wall. The Land of Footprints Likewise, removing an electron from a cation with a higher positive charge is more difficult than removing an electron from an ion with a lower charge. Chemistry 2019-02-14T00:00:00Z For ionic compounds, lattice energies are associated with many interactions, as cations and anions pack together in an extended lattice. Chemistry 2019-02-14T00:00:00Z The anions in simple ionic structures commonly adopt one of these structures, and the cations occupy the spaces remaining between the anions. Chemistry 2019-02-14T00:00:00Z Sodium chloride, NaCl, is comprised of Na+ cations and Cl− anions, and so oxidation numbers for sodium and chlorine are, +1 and −1, respectively. Chemistry 2019-02-14T00:00:00Z A salt is an ionic compound consisting of cations and anions. Chemistry 2019-02-14T00:00:00Z Write the complete electron configurations of these cations. Chemistry 2019-02-14T00:00:00Z The easy loss of this valence electron means that these metals readily form stable cations with a charge of 1+. Chemistry 2019-02-14T00:00:00Z Tin and lead form the stable divalent cations, Sn2+ and Pb2+, with oxidation states two below the group oxidation state of 4+. Chemistry 2019-02-14T00:00:00Z With difficulty, they form simple cations that are stable in water, and, unlike the earlier elements in the second and third transition series, they do not form stable oxyanions. Chemistry 2019-02-14T00:00:00Z This results in a cation with 20 protons, 18 electrons, and a 2+ charge. Chemistry 2019-02-14T00:00:00Z Write the electron structure of the two cations. Chemistry 2019-02-14T00:00:00Z Moving from the far left to the right on the periodic table, main-group elements tend to form cations with a charge equal to the group number. Chemistry 2019-02-14T00:00:00Z Predict which forms an anion, which forms a cation, and the charges of each ion. Chemistry 2019-02-14T00:00:00Z In every ionic compound, the total number of positive charges of the cations equals the total number of negative charges of the anions. Chemistry 2019-02-14T00:00:00Z For ionic compounds, it’s convenient to assign oxidation numbers for the cation and anion separately. Chemistry 2019-02-14T00:00:00Z Lewis symbols can also be used to illustrate the formation of cations from atoms, as shown here for sodium and calcium: Chemistry 2019-02-14T00:00:00Z For example, potassium nitrate, KNO3, contains the K+ cation and the polyatomic anion. Chemistry 2019-02-14T00:00:00Z The charges of cations formed by the representative metals may be determined readily because, with few exceptions, the electronic structures of these ions have either a noble gas configuration or a completely filled electron shell. Chemistry 2019-02-14T00:00:00Z Other distortions are found in impure crystals, as, for example, when the cations, anions, or molecules of the impurity are too large to fit into the regular positions without distorting the structure. Chemistry 2019-02-14T00:00:00Z In simple ionic structures, we usually find the anions, which are normally larger than the cations, arranged in a closest-packed array. Chemistry 2019-02-14T00:00:00Z For cations, subtract one electron for each positive charge. Chemistry 2019-02-14T00:00:00Z You can use the periodic table to predict whether an atom will form an anion or a cation, and you can often predict the charge of the resulting ion. Chemistry 2019-02-14T00:00:00Z Thus, a magnesium atom will form a cation with two fewer electrons than protons and a charge of 2+. Chemistry 2019-02-14T00:00:00Z Predict which forms an anion, which forms a cation, and the charges of each ion. Chemistry 2019-02-14T00:00:00Z The charges of cations and anions dictate their ratios in ionic compounds, so specifying the names of the ions provides sufficient information to determine chemical formulas. Chemistry 2019-02-14T00:00:00Z The Na+ cation is inert and will not affect the pH of the solution, while the anion is amphiprotic. Chemistry 2019-02-14T00:00:00Z Positively charged ions are called cations, and negatively charged ions are called anions. Chemistry 2019-02-14T00:00:00Z As all substances must be electrically neutral, the total number of positive charges on the cations of an ionic compound must equal the total number of negative charges on its anions. Chemistry 2019-02-14T00:00:00Z When a Ca atom loses both of its valence electrons, the result is a cation with 18 electrons, a 2+ charge, and an electron configuration of 1s22s22p63s23p6. Chemistry 2019-02-14T00:00:00Z Thus, the charge of a cation formed by the loss of all valence electrons is equal to the group number minus 10. Chemistry 2019-02-14T00:00:00Z The carbonate ion concentration is gradually increased in a solution containing equal concentrations of the divalent cations of magnesium, calcium, strontium, barium, and manganese. Chemistry 2019-02-14T00:00:00Z Chromium is a transition element and should lose its s electrons and then its d electrons when forming a cation. Chemistry 2019-02-14T00:00:00Z Compounds with a ratio of less than 2:1 may also crystallize in a closest-packed array of anions with cations in the tetrahedral holes, if the ionic sizes fit. Chemistry 2019-02-14T00:00:00Z Thus, compounds with cations in octahedral holes in a closest-packed array of anions can have a maximum cation:anion ratio of 1:1. Chemistry 2019-02-14T00:00:00Z In a simple cubic array of anions, there is one cubic hole that can be occupied by a cation for each anion in the array. Chemistry 2019-02-14T00:00:00Z When all other parameters are kept constant, doubling the charge of both the cation and anion quadruples the lattice energy. Chemistry 2019-02-14T00:00:00Z When an ionic compound is composed of a 1:1 ratio of cations and anions that differ significantly in size, it typically crystallizes with an FCC unit cell, like that shown in Figure 10.60. Chemistry 2019-02-14T00:00:00Z They can be described by FCC unit cells with cations in the octahedral holes. Chemistry 2019-02-14T00:00:00Z Still larger cations can occupy cubic holes in a simple cubic array of anions. Chemistry 2019-02-14T00:00:00Z The Na+ cation is inert and will not affect the pH of the solution; while the anion is amphiprotic. Chemistry 2019-02-14T00:00:00Z The represents the conversion of solid cesium into a gas, and then the ionization energy converts the gaseous cesium atoms into cations. Chemistry 2019-02-14T00:00:00Z Acidic cations are typically the conjugate partners of weak bases, and basic anions are the conjugate partners of weak acids. Chemistry 2019-02-14T00:00:00Z In addition, the presence of a variety of cations gives rise to the large number of silicate minerals. Chemistry 2019-02-14T00:00:00Z |
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