It decreases as you go down a group because the atomic radius increases, and the energy shells increase, so the attraction is less. also, the number of electrons going down a period also increase, so there is more repulsion, and its harder to add electrons.
Yes, that is part of the definition of electron affinity.
Electron affinity is the energy released when an electron is added to a neutral atom. Elements with a zero electron affinity value include neon, helium, and argon because they have stable electron configurations and do not readily accept additional electrons.
Oxygen.
Noble gases have completely filled orbitals / energy levels. They generally have 8 valence electrons (helium has only 2) and have stable electronic configuration. They will not accept any more electrons and hence they have positive electron affinity.
You think probable to the value of electronegativity.
Yes, that is part of the definition of electron affinity.
Electron affinity is the energy released when an electron is added to a neutral atom. Elements with a zero electron affinity value include neon, helium, and argon because they have stable electron configurations and do not readily accept additional electrons.
Oxygen.
Electron affinity is the amount of energy required to remove an electron from an atom. Or an energy released by adding an electron to a gaseous atom ( ie, negative quantity). In this case, if an element has a negative Electron Affinity, its indicating that this element is stable than the neutral ones.
Measure the equilibrium constant for the reaction of thermal electrons with a species at different temperatures. this has been done with an electron capture detector. another way to measure it is to make a negative ion and shine light on it and measure the energy of the electrons removed by this process Dr.Edward Chen
Electron affinity values for noble gases are endothermic because these elements have stable electron configurations and do not readily accept additional electrons. This makes it energetically unfavorable for them to gain an extra electron, resulting in a positive electron affinity value.
The electron affinity for phosphorus is -72 kJ/mol. This value represents the energy released when an electron is added to a neutral phosphorus atom to form a negatively charged ion.
An ionic bond forms when there is a large difference in electron affinity between two atoms. Typically, one atom has a high electron affinity (strongly attracts electrons) and the other atom has a low electron affinity (weakly attracts electrons), leading to the transfer of electrons from one atom to the other to form charged ions that are held together by electrostatic forces.
Electron affinity of chlorine is far grater than oxygen. For oxygen, its value is 141 KJ/mole whereas for Chlorine, it is 349 KJ/mole. Thus, adding an electron is more favourable in case of a gaseous chlorine atom
Noble gases have completely filled orbitals / energy levels. They generally have 8 valence electrons (helium has only 2) and have stable electronic configuration. They will not accept any more electrons and hence they have positive electron affinity.
AnswerElectron affinity is the energy released when we add an electron to the outermost orbit of the atom. Halogens are the higher in electron affinity, and chlorine has the higher electron affinity than rest of the halogens. The irregularity in the electron affinity trend between Cl and F is due to the small size of the F atom. Although F definitely has a higher attraction for an electron than Cl (as evidenced by its high electro negativity value), the small size of the F atom means that adding an electron creates significant repulsion. Since electron affinity is an energy measurement, the total energy associated with electron affinity winds up being the energy that is released by the electron binding to the nucleus, minus the energy involved in overcoming the electrical repulsion in the outer shell.This makes the fluoride anion so formed unstable due to a very high charge/mass ratio. Also, fluorine has no d electrons which limits its atomic size. As a result, fluorine has an electron affinity less than that of chlorine.
Generally electron affinity goes up as you go from left to right across the periodic table, and decreases as you go down a column. However, fluorine is an exception -- and the element with the highest electron affinity is chlorine.(Note that the most electronegative element is fluorine however; 'electronegativity' is not exactly the same as 'electron affinity'.)Electronegativity is the ability of an atom in a molecule to draw bonding electrons to itselfElectron affinity is a measure of the energy change when an electron is added to a neutral atom to form a negative ion.The reason that the electron affinity is not as high as might otherwise be predicted for fluorine, is that it is an extremely small atom, and so it's electron density is very high. Adding an additional electron is therefore not quite as favorable as for an element like chlorine where the electron density is slightly lower (due to electron-electron repulsion between the added electron and the other electrons in the electron cloud).