which of these isoelectronic ions is the largest? O^2-,F-,Na+,Mg^2+ or Al^3+? why?
150057
O2- is the largest ion because the no. of electrons are more and more widely distributed and nuclear charge become less......thats why as the -ve charge of isolectronic species increses the size of the atom also increases.
536511
If you mean atomic radius, the atoms.  The ions will most likely have shed their outer electrons to form the ion, such as Ca +2, while the atoms keep that outer shell, which increases the radius.\n\ndkrgrand:  That's the whole point.  The size of Ca (the metal) is bigger than the size of Ca+2 (the ion) because of the missing shell.  This is what was asked.
928933
The electron affinity is a measure of the energy change when an electron is added to a neutral atom to form a negative ion. For example, when a neutral chlorine atom in the gaseous form picks up an electron to form a Cl- ion, it releases an energy of 349 kJ/mol or 3.6 eV/atom. It is said to have an electron affinity of -349 kJ/mol and this large number indicates that it forms a stable negative ion. Small numbers indicate that a less stable negative ion is formed. Groups VIA and VIIA in the periodic table have the largest electron affinities.\n\n* Alkali earth elements (Group IIA) and noble gases (Group VIIIA) do not form stable negative ions. \n\nElectron Affinities in kJ/mole\nPeriod IA  IIIA  IVA  VA  VIA  VIIA  \nPeriod 1 H  ...  ...  ...  ...  ...  \n-73  ...  ...  ...  ...  ...  \nPeriod 2 Li  B  C  N  O  F  \n-60  -27  -122  0  -141  -328  \nPeriod 3 Na  Al  Si  P  S  Cl  \n-53  -44  -134  -72  -200  -349  \nPeriod 4 K  Ga  Ge  As  Se  Br  \n-48  -30  -120  -77  -195  -325  \nPeriod 5 Rb  In  Sn  Sb  Te  I  \n-47  -30  -121  -101  -190  -295  \nPeriod 6 Cs  Tl  Pb  Bi  Po  At  \n-45  -30  -110  -110  -180  -270  \n\n\n\nElectron Affinities in Electron Volts\n1 kJ/mol = .010364 eV/atom\nPeriod IA  IIIA  IVA  VA  VIA  VIIA  \nPeriod 1 H  ...  ...  ...  ...  ...  \n-0.76  ...  ...  ...  ...  ...  \nPeriod 2 Li  B  C  N  O  F  \n-0.62  -0.28  -1.27  0  -1.43  -3.41  \nPeriod 3 Na  Al  Si  P  S  Cl  \n-0.55  -0.46  -1.39  -0.75  -2.08  -3.62  \nPeriod 4 K  Ga  Ge  As  Se  Br  \n-0.50  -0.31  -1.25  -0.80  -2.02  -3.37  \nPeriod 5 Rb  In  Sn  Sb  Te  I  \n-0.49  -0.31  -1.26  -1.05  -1.97  -3.06  \nPeriod 6 Cs  Tl  Pb  Bi  Po  At  \n-0.47  -0.31  -1.14  -1.14  -1.87  -2.80  \n\nPeriodic Table  Chemical bonds
961493
You need to know more than just the electron configuration.  There is contraction from left to right on the periodic table, plus additional periodic trends that must be considered.   \n\nEven more importantly, you need to define whether you are looking for the largest element IN ITS NATURAL  STATE (i.e. Cl2, Hg metal, etc) or AS THE ION.   Atomic and ionic radii differ.\n\nMore clarity is needed here.
964369
Huge order. Let's see how far it can be served.\n\n1. Monoatomic negative ions: take the element name (sometimes shortened) and add "-ide" (as in hydride, nitride, oxide, sulphide, phosphide, chloride...)\nPositive ions: element-name, charge (if several charges are possible), ion (sodium ion, iron II ion...)\n\n2. Polyatomic ions:\nComplexes with various ligands list the ligands and the central ion/atom.\nOxygen as ligands has its own nomenclature, depending on oxidation state. E.g. Sulphate, sulphite, perchlorate, chlorate, chlorite, hypochlorite...\n\n3. Binary molecular compounds: Halogen, oxygen and sulphur compounds usually have the correspondent "-ide" as if you had ionic compounds. Usually the more electropositive element is used as center.\n\n4. Acids: Oxygen acids have a similar nomenclature to oxygen ions.
720109
Mn2+ is the common ion
343761
This is a homework question & better not be one of my students! LOL\n\nThe answer is atom.\n\nClassic textbook question. For those of you who thought the question was confusing, take it up w/ the authors of high school textbooks. I will gladly back you up on it. LOL\n\n:)
805536
Yes, then it is a called a cation.  The element still contains its protons and therefore gives the ion a positive charge.  \n\nHowever, the electron configuration of the element determines what ions you can make as the stability will drastically fall with the more electrons removed
791152
The chemical formula of potassium alum is KAl(SO4)2.\nThe bonding type is mixed. The K+ and Al3+ ions are bonded ionically to the (SO4)2- ions. But in the latter the bonds are rather covalent as the S atom retains hold on its electrons at least part of the time.
649164
Francium and cesium are about 0.5.\nFluorine is highest at 3.9-4.0 (by Pauling's estimate)
274092
All ionic compounds dissociate into respective +ve and -ve ions in aquous solutions.\n\nYou possibly want to know such compounds which give both +ve and -ve ions with more than 1 charge.\n\nYes salts of all alkline earth metals (+ve2) with ions of more than one atoms (CO3,PO4 etc) having more than 1 -ve charge dissociate in the way you need to know.
714217
The metal which is the furtherest to the right-hand top corner of the periodic table will be the most electronegative. Those who said fluorine didn't read the question properly because you are asked for a metal and fluorine, although the most electronegative 'element', is not a metal. In answering this question, I'm going to assume that the metalloids aren't included and not a subset of the cagetory of metals. The most electronegative metal would be aluminium (13). Have a look at the periodic table, it's the element which is closest to the top-right hand side but is still classified as a metal.
570227
Na is larger than Na+.\nF is larger than F+.\nCations are always smaller than the parent atom as the effective nuclear charge acting on an electron increases as the total number of electrons decreases.\nIn the case of Na&Na+,Na+ has one whole shell lesser than Na.
327351
The previous answer is correct if an equal number of moles is dissolved.  If you were looking at a saturated solution, it would be LiCl, which can dissolve in greater quantities than any other salt, even greater than NaCl. (36 g of NaCL will dissolve in 100 ml water compared to 55 grams LiCl per 100 ml water). The Li+ ion is very very small-it's only larger than hydrogen and helium. For an equal weight of LiCl and Al(NO3)3 dissolved in water, LiCl would also have a greater effect, because of the greater number of ions per gram.  Thus, in either a saturated solution or a weight to volume solution, LiCl would produce the greater number of ions, whereas it would not in a equamolar solution.  LiCl is used a great deal in density experiments, because you can make a very dense aqueous solution of it, and in reducing freezing point, since you can get the maximum number of ions of any aqueous solution, so the questioner is probably looking for LiCl.
964292
Ignoring the inert gases, the highest electronegativity is at the top right corner (fluorine), and the lowest is at the bottom left (francium)
29852
It isn't. the magnesium ion has a radius of 0.85 angstroms while the sodium ion has a radius of 1.16 angstroms.
876338
All three of these ions have the same number of electrons, they are "isoelectronic."  The size of the ions thus depends on the number of protons in the nucleus.  As we move to the right across a row on the periodic table, the number of protons in the nucleus, and thus the nuclear charge, increases.  This increase in nuclear charge pulls the electrons in tighter, thus reducing the size of the ions.  Na+ > Mg2+ > Al3+