what is electron affinity?
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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
1094405
A covalent bond is a bond in which the atoms making up the resulting molecule "share" the electrons in the form of covalent bonds.\nAn ionic bond is an extremely one sided "sharing" of electrons, so one sided, one atom is said to have completely stripped of an electron from another atom.\n\nWhat determines if the bond is covalent or ionic is the difference in the electronegativities of the two atoms bonding.  If the electronegativity difference is high enough, the bond is said to be ionic.  If the difference in electronagativities is significant, but not quite to the level of a full ionic bond, the bond is said to be polar (which may or may not mean that the resulting molecule is polar, this depends on several things).\n\nLooking at a chart of [Pauling] electronegativities,\nhttp://www.psigate.ac.uk/newsite/reference/plambeck/chem1/p01244a.htm\none can see that most elements are somewhere in the 1 to 2 range, with only a few elements getting much lower or higher than this value.  Unless the difference is high enough (usually a difference of about 1.5 is considered ionic), then the bond will just be polar, or less so.\n\nSo, all elements have the potential to theoretically bond ionically, but only in certain combinations with other elements.\nFor example, you will never see an ionic bond between Carbon and Hydrogen since the difference is just .4, but an ionic bond between Lithium and Fluorine is easy to make with a huge difference of 3.0.
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In a covalent bond, both species provide 1 electron to form the 2 electron bond.\n\nIn a complex, both bonding electrons are donated from a single atom. Complexation refers to the formation of complex bonds.
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when a ligand has highly electronegative elements at its ends like O- or NH- etc. it tends to share its electrons by donating them to empty orbitals of the metals and lead to the formation of complexes called ion-association complexes.\n\nwhen  more than one such higly electronegative sites are present in the same ligand (like ETDA,gelatin, ethylene di amine , etc.) these tend to form intra-molecular rings with the\nmetal atom , these are called chelating agents.
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both positively and negative atoms have affinity for each other\n\nthis is due to the reason that each of them has few +ve particles \nand few -ive particles.this attract each other due their affinity\nbut both +ve and -ive atoms have protons(+ve particles) and electrons (-ive particles) in higher number therefore its always an over coming force this gives rise to an attraction or repelling force respectively on opposite and same type of charge
161637
ionic,the diference in electronegativity values is greater then 1.6.  the metal bonded to a non metal method is also correct
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do the project on electronic configurations of different elements or on the characteristics of each element in the periodic table such as lithium is the metal lighter than water, element with highest affinity is chlorine and things like that. u can do this for each and every element. another thing is that the periodic table has been completed so u can do some project relating to that.
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a polar bond is one which the shared electron, making the bond, is closer to one atom.  A bond between two identical atoms is non-polar because the atoms have the same electronegativity.\n\nElectronegativity is the affinity for an electron.  Fluorine is the most electronegative element and Francium the least.\n\nHydrogen has an electronegativity of 2.2 and fluorine 3.98, prompting the electrons to be closer to fluorine, consequently making the hydrogen partially positive and fluorine slightly negative.
466437
interesting answer above.\n\nCarbon has 4 valance electrons which because of the relatively small size of the atom can move about and create all sorts of hybrid orbitals and molecular bonding orbitals allowing it to suit the bonding needs of many other atoms, thus making many varied combinations.\n\nIt is also in the middle range of electronegitivities therefore resisting in most situations becoming an ion.
886720
Thats simple,\nAs we rub together two surfaces, there is friction and hence the two close atoms are rubbed together which results in transfer of electrons...\nThe subs in which electrons are transfered is negatively charged (by convention electrons are supposed to have negative charge) and from which they are transfred is said to be positivly charged...
193226
All atoms do this. The Noble gasses have the most stable electron configurations because they fill/do not have "open shells".\n\nFor example, Calcium's nearest noble gas is behind it, so it will LOOSE two electrons, since losing two is easier than gaining 6 to act like the next noble gas ahead of it, that's why you see Calcium as a 2+ ion. (Ca2+). Iodine, on the other hand needs to gain one electron (instead of losing 7) to be like it's nearest noble gas, so you get the ion of I-. For a metal like silver, it just has one "valance" electron, so you'll see silver as Ag+. Copper has two extra : Cu2+, Iron typically has 3 valance electrons so it make Fe3+
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An ion is formed when one electron completely transfers over from one atom to another atom.  The one losing the electron acquires a positive charge and the one losing the electron acquires a negative charge.  But then these two ions are attracted to each other forming an ionic compound.  After coming together, the bonding electrons spend most of the time around the atom with the negative charge, that is, the more electronegative ion.  However, there are also moments when the electrons get closer to the electropositive atom.  Though it's rare to find the bonding electrons near the electropositive atom (since it's orbitals are higher in energy), calculations find that ~5% of the time the electrons are closer to the electropositive atom than to the electronegative atom.  (Don't trust me on the ~5%... this is based on only a few examples from my Inorganic Chemistry chapter I read a few weeks ago).  A popular example is that of HF.  If you use molecular orbital diagrams, you see that the 2s orbital is so low in energy (around -40eV) that it doesn't share it's electrons.  The 2p(z) orbital bonds with the hydrogen's 1s orbital but you'll see that the resulting bonding orbital is so close to the 2p(z) orbital in energy that you can sort of consider it somewhat nonbonding.  The point is that there is little influence from the H 1s orbital, but there is still a small amount of influence.  This means the bonding electrons spend a fraction of the time around the H atom, meaning that the original electron in question has no completely transferred over to the F atom.
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During electrolysis, the oxygen atom in H20 has 2 pairs of unbonded electrons, and it is these electrons that act as "solvents" breaking the bond between atoms and attacking the postive ion that forms as a result.  So you can visualize a solution as islands of ions surrounded by water ions, with the extra electrons of oxygen surrounding the positive ions and the negative ions surrounded by the hydrogens of water.  \n\nA "strong" electrolyte is one that dissociates almost completely into ions i.e the water molecules break its bond and surround its ions easily.  HCl is a good example.  HF is an exception.  Since F is the element with the strongest electronegativity (4.0) it forms very strong bonds.  And, apparently, water molecules just don't have the ability to break the H-F bond, so very little of HF ionizes in water.    Talking about HF, it is one of the few compounds (and as far as I know, the only compound) that can attack glass (Si03) to form fluorosilicates.
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Electron configuration is related to the number of protons in the nucleus, hence, the element. In theory, all isotopes of a certain element should have the same electron configuration.\n\nWhat u were asking for is an electron configuration for oxygen anion, it has the same electron configuration as Neon\n\nelectron configuartion of O^2- = [Ne] (Neon core) = 1s^2 2s^2 2p^6
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all the electrons are located in the electronic orbitals of the ion.\n\nYou may find this useful:\n\nhttp://www.owlnet.rice.edu/~chem251/documents/Vollhardt_1.ppt
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"Normal" bonding occurs when a ligand donates electrons to a metal. When a metal ion donates electrons back to the ligand, this is called back-bonding. The combination of normal bonding and back-bonding creates a strong bond between the ligand and the metal. The reason that phosphines, carbon monoxide, and cyanide are so poisonous is because they bond readily to iron in biological systems and cannot be displaced by the ligands (such as oxygen) which should bond to iron in normal metabolic processes.
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um...  subtract???  hahaha\n\nThe higher the differences in electronegativity, the more ionic the compound.  The higher electronegative atom/ion will want to "hog" all the electrons.  They are greedy like that.  They don't want to share (which would be a covalent bond).