Sulfur charge ion - If you’ve ever taken a basic chemistry course, you know the substance we casually call “salt” is merely one kind of salt. A salt is simply a chemical compound consisting of a posit...

 
Sep 15, 2022 · Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as \(\ce{NaNaS}\), we shorten it by convention to \(\ce{Na2S}\). The aluminum ion has a 3+ charge, while the fluoride ion formed by fluorine has a 1− charge. . Howard stern marci turk

Dear Lifehacker, What is the deal with lithium-ion batteries (the kind found in smartphones and laptops)? I've heard lots of different things about how to take care of them, like t...Sulfur and selenium-based lithium metal and sodium metal batteries (LMBs and SMBs) are an exciting emerging class of “Beyond Li” architectures. While the Se x S y system has received limited attention for LMBs, for SMBs it remains mostly unexplored. We report a new SeS-based cathode with pyrolyzed polyacrylonitrile host.Apr 25, 2024 · 18 18. . Thus, sulphur when turned into ion it carries the charge of. −2 − 2. , as sulphur usually gains two electrons to get stability. Note: The atom or chemical element tries to gain or lose electrons to attain the nearest noble gas configuration, the element belonging to the oxygen family tries to gain two electrons. Figure2.7.3 2.7. 3: Example of some compounds that have multiple oxidation states. Note mercury (1) is not a monoatomic cation, but is really a homonuclear diatomic ion of two mercury atoms bound to each other, both having lost one electron. So Hg 2 Cl 2 it the lowest whole number ratio of cation to anion. Example 2.If you remember the exploding Samsung Galaxy Note 7 fiasco, you wouldn't be surprised why aviation security is so worried about lithium-ion batteries. I’ve had the distinct displea...In this video we will write the electron configuration for S 2-, the Sulfide ion. We’ll also look at why Sulfur forms 2- ion and how the electron configurati...Jun 26, 2023 · Figure 4.4.3 4.4. 3: Predicting Ionic Charges. The charge that an atom acquires when it becomes an ion is related to the structure of the periodic table. Within a group (family) of elements, atoms form ions of a certain charge. Be sure to memorize silver (Ag+) and zinc (Zn2+) charges in addition to this chart. Watch this video to find out about the EGO Power+ cordless string trimmer powered by a 56-volt, lithium-ion battery for increased performance and run time. Expert Advice On Improvi...Herein, we developed a dual PS-LiI catholyte to simultaneously alleviate the shuttling of iodine and the passivation of Li 2 S, demonstrating stable ion-selective membrane-free Li-catholyte cells achieving volumetric capacity between 30–60 Ah L −1 catholyte with long cycle life (>150 cycles) at high current densities (3.8 mA cm −2 and …Our sulfur page has over 300 facts that span 107 different quantities. Each entry has a full citation identifying its source. Areas covered include atomic structure, physical properties, atomic interaction, thermodynamics, identification, atomic size, crystal structure, history, abundances, and nomenclature.About. Transcript. Definition of formal charge, and how minimization of formal charge can help choose the more stable dot structure. Created by Jay. Questions. Tips & Thanks. …To find the formula of an ionic compound, first identify the cation and write down its symbol and charge. Then, identify the anion and write down its symbol and charge. Finally, combine the …Sulfur and selenium-based lithium metal and sodium metal batteries (LMBs and SMBs) are an exciting emerging class of “Beyond Li” architectures. While the Se x S y system has received limited attention for LMBs, for SMBs it remains mostly unexplored. We report a new SeS-based cathode with pyrolyzed polyacrylonitrile host.The stable ion the sulfur would form is the sulfide ion, S 2 −. A neutral sulfur atom contains 16 electrons. We can know this because its atomic number is 16, which means there are 16 protons in the nucleus. Since the negative charge of the electrons cancels the charge of the protons, the sulfur atom is neutral.PCl 3. Sulfur forms three chlorides, but S 2 Cl 2 is most common. Aluminum chloride also exists under some conditions as a dimer, Al 2 Cl 6. The structures: Sodium chloride and magnesium chloride are ionic and consist of large ionic lattices at room temperature. Aluminum chloride and phosphorus (V) chloride are more complicated.Lithium-sulfur batteries (LiSB) are promoting as one of the next-generation batteries using elemental sulfur (S 8) as a positive electrode active material, which is easily available and inexpensive.Elemental sulfur has a large theoretical capacity of 1672 mAh g –1.However, there are some issues toward its realization; obtaining the theoretical capacity is difficult …In this case, the sulfur atom carries a negative charge. S + 2e – → S 2-. Here, the electron configuration of sulfide ion (S 2-) is 1s 2 2s 2 2p 6 3s 2 3p 6. This negative sulfide ion (S 2-) has sixteen protons, sixteen …The sulfate ion carries an overall charge of −2 and it is the conjugate base of the bisulfate (or hydrogensulfate) ion, HSO− 4, which is in turn the conjugate base of H2SO4, sulfuric …We need two Cl − ions to balance the charge on one Ca 2+ ion, so the proper ionic formula is CaCl 2. We need three F − ions to balance the charge on the Al 3+ ion, so the proper ionic formula is AlF 3. With Al 3+ and O 2−, note that neither charge is a perfect multiple of the other. This means we have to go to a least common multiple ...The main attraction is that they can store much more energy than a similar battery using current lithium-ion (Li-ion) technology. That means they can last substantially longer on a single charge.They can also be manufactured in plants where Li-ion batteries are made – so it should be relatively straightforward to put them into production.Formal charge on the single bonded Oxygen atom = 6 – 6 – 2/2 = 6 – 6 – 1 = 6 – 7 = -1. ∴ The formal charge on each single-bonded oxygen (O) atom in [SO4]2- is -1. For double-bonded oxygen atoms. Valence electrons of oxygen = It is present in Group VI A = 6 valence electrons. Bonding electrons around Oxygen = 1 double bond = 4 electrons.Figure 3.2.2 3.2. 2: The Formation of a Chlorine Ion. On the left, the chlorine atom has 17 electrons. On the right, the chloride ion has 18 electrons and has a 1− charge. With two oppositely charged ions, there is an electrostatic attraction between them because opposite charges attract.Thus, it is simple to determine the charge on such a negative ion: The charge is equal to the number of electrons that must be gained to fill the s and p orbitals of the parent atom. Oxygen, for example, has the electron configuration 1 s 2 2 s 2 2 p 4 , whereas the oxygen anion has the electron configuration of the noble gas neon (Ne), 1 s 2 2 ...Figure2.7.3 2.7. 3: Example of some compounds that have multiple oxidation states. Note mercury (1) is not a monoatomic cation, but is really a homonuclear diatomic ion of two mercury atoms bound to each other, both having lost one electron. So Hg 2 Cl 2 it the lowest whole number ratio of cation to anion. Example 2.Apr 21, 2018 ... In order to calculate the formal charges for SF6 we'll use the equation: Formal charge = [# of valence electrons] - [nonbonding val ...If you’ve ever taken a basic chemistry course, you know the substance we casually call “salt” is merely one kind of salt. A salt is simply a chemical compound consisting of a posit...Sulfur is an essential component of all living cells. It is the eighth most abundant element in the human body by weight, [98] about equal in abundance to potassium, and slightly greater than sodium and chlorine. [99] A 70 kg (150 lb) human body contains about 140 grams (4.9 oz) of sulfur. [100]The 5-atom unit (1 x S, 4 x O) has an overall charge of -2. (It is incorrect to think that the oxygen has a -2 charge OR the sulfur has a -2 charge) In general, the atoms of a polyatomic ions (and the associated overall charge) stay together whether you are writing the ion by itself or as a part of a formula.Sep 15, 2016 · The stable ion the sulfur would form is the sulfide ion, "S"^(2-). A neutral sulfur atom contains 16 electrons. We can know this because its atomic number is 16, which means there are 16 protons in the nucleus. Since the negative charge of the electrons cancels the charge of the protons, the sulfur atom is neutral. The electron configuration of sulfur is "1s"^2"2s"^2"2p"^6"3s"^2"3p"^4". The ... The lithium–sulfur battery (Li–S battery) is a type of rechargeable battery.It is notable for its high specific energy. The low atomic weight of lithium and moderate atomic weight of sulfur means that Li–S batteries are relatively light (about the density of water). They were used on the longest and highest-altitude unmanned solar-powered aeroplane flight (at the …Positive ions are cations. When there are more electrons than protons, as in the case of the sulfur ion, the net charge is negative [(+16) + (−18) = −2]. Negative ions …Similar to fluorine, sulfur aims to achieve a full outer electron shell. To do this, it tends to gain two electrons, giving it a charge of -2. Therefore, in ionic compounds, sulfur usually carries a negative charge. Sulfur in Chemical Compounds. When sulfur reacts with metals, it forms ionic compounds.That is, sulfur is an anion element. S + 2e – → S 2-. The electron configuration of sulfide ion (S 2-) is 1s 2 2s 2 2p 6 3s 2 3p 6. This electron configuration shows that sulfide ion (S 2-) has three shells and the 3rd shell has eight electrons.On the contrary, in Li-S cells, Sulphur reacts with Lithium ions when reduced from elemental state S 8, via the intermediates Li 2 S 8, Li 2 S 4, Li 2 S 2, to Lithium sulphide Li 2 S depending on the State of Charge (SOC) (Fotouhi et al., 2016b, Propp et al., 2016).About. Transcript. To find the formula of an ionic compound, first identify the cation and write down its symbol and charge. Then, identify the anion and write down its symbol and … Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as \(\ce{NaNaS}\), we shorten it by convention to \(\ce{Na2S}\). The aluminum ion has a 3+ charge, while the fluoride ion formed by fluorine has a 1− charge. Three fluorine 1− ions are needed to balance the 3+ charge on the aluminum ion. The results presented from our sulfur L-shell measurements are the first to report on individual transitions formed by charge exchange. In the CX spectra, we found a significant enhancement in the transitions n = 4, 5, 6 → n = 2, in comparison with the n = 3 → n = 2 transitions that dominate direct excitation.Positive ions are cations. When there are more electrons than protons, as in the case of the sulfur ion, the net charge is negative [(+16) + (−18) = −2]. Negative ions are anions. Complete the following table and consider how you would explain your answers if you were teaching this concept to a peer.Our sulfur page has over 300 facts that span 107 different quantities. Each entry has a full citation identifying its source. Areas covered include atomic structure, physical properties, atomic interaction, thermodynamics, identification, atomic size, crystal structure, history, abundances, and nomenclature.Know All about Sulfite Ion Structure, Formula, and Charge. Sulfite ion is formed by one centered sulfur cation S4+ and three oxygen anions O2-. The geometry is a trigonal pyramid with the three oxygen atoms forming the base and over the sulfur atom, there is a lone pair of electrons. The molar mass is 80.06 g/mol.However, the real-world cycle life may be shorter with fast charging, more like 1,000 cycles, he says. This is considered a ten-year lifespan. Along with the higher capacity, lithium-sulfur batteries have sustainability advantages over other lithium-ion batteries. Sulfur is much more abundant than the cobalt of lithium-ion electrodes.Key Points: † Energetic oxygen and sulfur charge states inferred from ion dispersion theory † Sulfur is predominantly multiply charged, whereas oxygen is both singly and doubly charged † Charge gain plays an important role on energetic oxygen-neutral interactions in the Europa torus Correspondence to: G. Clark, [email protected] ...Ionic compounds containing hydrogen ions (H+) are classified as acids, and those containing hydroxide (OH−) or oxide (O2−) ions are classified as bases. All other ionic compounds without these ions are known as salts. Ionic compounds typically have high melting and boiling points, and are hard and brittle.In this video we'll write the correct formula for Sulfide ion (S 2-). To write the formula for Sulfide ion we’ll use the Periodic Table and follow some simpl...What is the Ionic Charge of Sulfur (S)? And Why? May 26, 2023 by Jay Rana. The Ionic Charge of Sulfur (S) is 2-. But the question is how can you find the ionic …Oxidation-Reduction: \ (\ce {S2^ {-}}\) or \ (\ce {H2S}\) can be oxidized to yellow elemental sulfur in a colloidal form with fairly mild oxidizing agents, including nitric acid. This page titled Sulfide Ion (S²⁻) is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by James P. Birk. Was this article helpful?Positive ions are cations. When there are more electrons than protons, as in the case of the sulfur ion, the net charge is negative [(+16) + (−18) = −2]. Negative ions are anions. Complete the following table and consider how you would explain your answers if you were teaching this concept to a peer.A neutral sulfur atom has six valence electrons, so the oxidation state of the central sulfurs can be calculated as follows: $$6 - 4 - \frac{1}{2}(4) = 0$$ That is, six electrons in neutral sulfur, minus four from the lone pairs, minus half of the four sulfur-sulfur bonding electrons, gives zero.Dawning technology is donned by Dawn. The NASA spacecraft Dawn has spent more than seven years traveling across the solar system to intercept the asteroid Vesta and the dwarf plane...A neutral sulfur atom has six valence electrons, so the oxidation state of the central sulfurs can be calculated as follows: $$6 - 4 - \frac{1}{2}(4) = 0$$ That is, six electrons in neutral sulfur, minus four from the lone pairs, minus half of the four sulfur-sulfur bonding electrons, gives zero.Sulfide ion, also knwn as S2-, is a negatively charged ion formed by the addition of two electrons to a neutral sulfur atom. The resulting ion has a charge of -2, which is represented as S2-. The formula for sulfide ion is relatively simple, as it consists of only one sulfur atom and two electrons. The chemical equation for the formation of ...Sulphur (also sulfur) is an element. It can be both uncharged and charged. In pure form sulfur is uncharged. As sulfide ions is has charge -2. In many molecules (like the amino acid custeine) and ...Jan 1, 2017 ... Is CO3 2- Polar or Nonpolar? (Carbonate ion). Wayne Breslyn•18K views · 1:29 · Go to channel · Intermolecular Forces for CO2 (Carbon dioxide).Two main reasons are responsible for the improved capacitance of S-Co 3 O 4 as follows: 1) The S-Co 3 O 4 has more oxygen vacancies, which favors the OH − ion adsorption. 2) The electronegativity of oxygen is higher than sulfur, while the atomic radius of O is smaller than S, so Co O bond is more stable than Co S bond. Solution Because the ionic compound must be electrically neutral, it must have the same number of positive and negative charges. Two aluminum ions, each with a charge of 3+, would give us six positive charges, and three oxide ions, each with a charge of 2−, would give us six negative charges. The formula would be Al 2 O 3. In (b), the sulfur atom has a formal charge of 0. In (c), the sulfur atom has a formal charge of 1+. Continuing with the nitrogen, we observe that in (a) the nitrogen atom shares three bonding pairs and has one lone pair and has a total of 5 valence electrons. The formal charge on the nitrogen atom is therefore 5 - (2 + 6/2) = 0.S doping facilitated OH − adsorption, conductivity and Faradaic reaction kinetics, thereby the specific capacitance of S-Co 3 O 4 has increased by ~7.8 times, compared with Co 3 O 4. S-Co 3 O 4 @CF//AC@CF asymmetric micro-supercapacitor (AMC) exhibits a greatly improved energy storage performance. Download : Download …The formal charge on each hydrogen atom is therefore. formalcharge(H) = 1 −(0 + 2 2) = 0 . The formal charges on the atoms in the NH 4+ ion are thus. Adding together the formal charges on the atoms should give us the total charge on the molecule or ion. In this case, the sum of the formal charges is 0 + 1 + 0 + 0 + 0 = +1.Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as \(\ce{NaNaS}\), we shorten it by convention to \(\ce{Na2S}\). The aluminum ion has a 3+ charge, while the fluoride ion formed by fluorine has a 1− charge. Three fluorine 1− ions are needed to balance the 3+ charge on the …Each oxygen atom will get a -1 charge and sulfur atom get a +2 charge. The overall charge of ion is ( -1*4 + (+2) ) = -2. Check the stability and minimize charges on atoms by converting lone pairs to bonds. When charges exist everywhere (on atoms) in the ion or molecule, that structure is not stable.Figure 1 is a typical room temperature sodium-sulfur battery charge/discharge curve, with two potential platforms of 2.20 V and 1.65 V during discharge, and two potential slope discharge regions within the potential range of 2.20–1.65 V and 1.60–1.20 V. There are two potential platforms of 1.75 V and 2.40 V when charging.As a result, G4 to coordinate the Li + ion is insufficient and the Li + ion dissolution is suppressed, increasing the charge transfer resistance of the negative electrode. For the positive electrode interface, with increasing C-rate, the concentration gradient becomes larger and the concentration of Li + ions on the interface decreases.In each resonance structure, the sulfur atom is double-bonded to one oxygen atom with a formal charge of zero (neutral), and sulfur is singly bonded to the other two oxygen … To obtain a valence shell octet, sodium forms an ion with a 1+ charge, while the sulfur ion has a 2− charge. Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as NaNaS, we shorten it by convention to Na 2 S. The aluminum ion has a 3+ charge, while the fluoride ion formed by fluorine ... The KCNJ5 gene provides instructions for making a protein that functions as a potassium channel, which means that it transports positively charged atoms (ions) of potassium (K + ) ... The sulfur atom is in the +6 oxidation state while the four oxygen atoms are each in the −2 state. The sulfate ion carries an overall charge of −2 and it is the conjugate base of the bisulfate (or hydrogensulfate) ion, HSO − 4, which is in turn the conjugate base of H 2 SO 4, sulfuric acid. Sulfur-Rich Additive-Induced Interphases Enable Highly Stable 4.6 V LiNi 0.5 Co 0.2 Mn 0.3 O 2 ||graphite Pouch Cells. ... Wenzhou Key Laboratory of Sodium-Ion …Nov 11, 2018 ... First, since the Sulfite ion has an overall charge of 2- we could say that the oxidation numbers in SO3 2- need to add up to charge on the ion ...To obtain a valence shell octet, sodium forms an ion with a 1+ charge, while the sulfur ion has a 2− charge. Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as \(\ce{NaNaS}\), we shorten it by convention to \(\ce{Na2S}\).Physical Properties of Sulfur. Sulfur has an atomic weight of 32.066 grams per mole and is part of group 16, the oxygen family. It is a nonmetal and has a specific heat of 0.706 J g -1 o C -1. The electron affinity is 200 kJ mol -1 and the electronegativity is 2.58 (unitless).If we use these guidelines to predict the charge on a sulfur ion, which is in group 16, we predict that the magnitude of the charge is 8 − 6 = 2 ‍ since sulfur has six valence electrons. We can also find the number of valence electrons by checking sulfur's group number, group 16, which has a 6 ‍ in the 1 ‍ s place.Thus, a nitrogen atom will form an anion with three more electrons than protons and a charge of 3−. The symbol for the ion is N 3−, and it is called a nitride ion. Check Your Learning Aluminum and carbon react to form an ionic compound. Predict which forms an anion, which forms a cation, and the charges of each ion.To obtain a valence shell octet, sodium forms an ion with a 1+ charge, while the sulfur ion has a 2− charge. Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as NaNaS, we shorten it by convention to Na 2 S. The aluminum ion has a 3+ charge, while the fluoride ion formed by fluorine ...2.7: Ions and Ionic Compounds is shared under a CC BY-NC-SA 3.0 license and was authored, remixed, and/or curated by LibreTexts. The atoms in chemical compounds are held together by attractive electrostatic interactions known as chemical bonds. Ionic compounds contain positively and negatively charged ions in a ratio that ….Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. And thus finally, if we have the 32S2− ion, there are 18 electrons, 16 protons, and 16 neutrons. For ""^32S^ (2-), there are 16 protons, 18 …Figure2.7.3 2.7. 3: Example of some compounds that have multiple oxidation states. Note mercury (1) is not a monoatomic cation, but is really a homonuclear diatomic ion of two mercury atoms bound to each other, both having lost one electron. So Hg 2 Cl 2 it the lowest whole number ratio of cation to anion. Example 2.The results presented from our sulfur L-shell measurements are the first to report on individual transitions formed by charge exchange. In the CX spectra, we found a significant enhancement in the transitions n = 4, 5, 6 → n = 2, in comparison with the n = 3 → n = 2 transitions that dominate direct excitation.Dawning technology is donned by Dawn. The NASA spacecraft Dawn has spent more than seven years traveling across the solar system to intercept the asteroid Vesta and the dwarf plane...Structure The structure of the sulfite anion Sulfite is a ligand in coordination chemistry.The structure of Co(ethylenediamine) 2 (SO 3)N 3.The structure of the sulfite anion can be described with three equivalent resonance structures.In each resonance structure, the sulfur atom is double-bonded to one oxygen atom with a formal charge of zero …

Ionic compounds containing hydrogen ions (H+) are classified as acids, and those containing hydroxide (OH−) or oxide (O2−) ions are classified as bases. All other ionic compounds without these ions are known as salts. Ionic compounds typically have high melting and boiling points, and are hard and brittle.. Chickens by the lake gossip

sulfur charge ion

Aug 25, 2020 ... ... IONIC because it is made from a metal and non-metal. A calcium atom loses two electrons to become +2 charged A sulfur atom gains those two ...Structure The structure of the sulfite anion Sulfite is a ligand in coordination chemistry.The structure of Co(ethylenediamine) 2 (SO 3)N 3.The structure of the sulfite anion can be described with three equivalent resonance structures.In each resonance structure, the sulfur atom is double-bonded to one oxygen atom with a formal charge of zero … Figure2.7.3 2.7. 3: Example of some compounds that have multiple oxidation states. Note mercury (1) is not a monoatomic cation, but is really a homonuclear diatomic ion of two mercury atoms bound to each other, both having lost one electron. So Hg 2 Cl 2 it the lowest whole number ratio of cation to anion. Example 2. The formal charge of sulfur in a sulfate compound is zero. This is due to its six different resonance structures. ... In order to understand why this polyatomic ion has a charge, the formal charge ... The stable ion the sulfur would form is the sulfide ion, S 2 −. A neutral sulfur atom contains 16 electrons. We can know this because its atomic number is 16, which means there are 16 protons in the nucleus. Since the negative charge of the electrons cancels the charge of the protons, the sulfur atom is neutral. Sulfur cathodes, based on the conversion-reaction electrochemistry in lithium−sulfur (Li−S) batteries, have become attractive in the last few decades due to their high theoretical capacity of ...Frasch process. 18.12: The Chemistry of Sulfur is shared under a license and was authored, remixed, and/or curated by LibreTexts. Sulfur (group 16) reacts with almost all metals and readily forms the sulfide ion, S2−, in which it has as oxidation state of 2−. Sulfur reacts with most nonmetals.Abstract Rechargeable lithium−sulfur (Li−S) batteries are one of the most promising next-generation energy storage systems due to their extremely high energy densities and low cost compared with state-of-the-art lithium-ion batteries. However, the main obstacles of conventional Li−S batteries arise from the dissolution of lithium polysulfides in organic liquid electrolytes and ...Frasch process. 18.12: The Chemistry of Sulfur is shared under a license and was authored, remixed, and/or curated by LibreTexts. Sulfur (group 16) reacts with almost all metals and readily forms the sulfide ion, S2−, in which it has as oxidation state of 2−. Sulfur reacts with most nonmetals.To give a brief quantitative overview of electric charge, the unit for charge is the Coulomb, denoted by "C". A proton has a charge of +1.602 ⋅ 10−19 and an electron has a charge of −1.602 ⋅ 10−19. These are referred to as the elementary charge. Note: While it is a good model to think of conservation as an inability to increase or ...What is the charge on its ions, and is the charge positive or negative? The charge is negative, since sulfur is a non-metal. The charge on the ion is (8 - 6) = 2.In the present paper, extensive results on charge fraction evolution for 2.0 MeV/u sulfur ions of all the initial charge states between 6+ and 14+ are presented, adding new data for 1.1 μg/cm 2 target to check the overshooting feature in the distribution width around 1 μg/cm 2 target thickness. 2. Experiment Ionic compound formed from iron and oxygen (assume the iron ion takes on a 3+ charge) SOLUTION. To obtain a valence shell octet, sodium forms an ion with a 1+ charge, while the sulfur ion has a 2− charge. Two sodium 1+ ions are needed to balance the 2− charge on the sulfide ion. .

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