Fluorine does not have the highest electron affinity it has highest electronegativity the highest electron affinity is for chlorine atom.
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Selenium does not have a second electron affinity because adding an additional electron to selenium would require more energy to overcome the repulsion between the negatively charged electron and the negatively charged selenium ion. In other words, the energy required to add a second electron to selenium is higher than the energy released in the process.
The energy released on adding an electron to an isolated gas phase atom is called electron affinity. It represents the willingness of an atom to accept an additional electron. The process can release energy if the atom's electron affinity is negative, indicating that the atom is stable after gaining an electron.
The highest energy electron in uranium is found in the 5f subshell. Uranium has 92 electrons, so the configuration for the highest energy electron would be [Rn] 5f³ 6d¹ 7s².
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.
It would be most difficult to remove an electron from chlorine because it has the highest electron affinity among the elements mentioned. Sodium has the lowest ionization energy, meaning it's easiest to remove an electron from it.
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).
Chlorine (Cl) would most likely have a positive electron affinity. Typically, elements with high electron affinities are found on the right side of the periodic table, closer to the noble gases. Among the choices given, Argon (Ar) is a noble gas and has a positive electron affinity.
Last time i cheacked it could be Be
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).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).Note that there are a number of other exceptions to the general rule of electron affinity increasing towards the upper right corner -- see the Related Questions links to the left for an explanation of some of those other exceptions.See also the Web Links to the left for more information about electron affinities and the fluorine-chlorine exception.
Fluorine has a lower electron affinity than oxygen. This is because fluorine already has a full outer shell of electrons and adding another electron would create repulsion due to electron-electron interactions. Oxygen, on the other hand, has space in its outer shell to accept an additional electron more easily.
Selenium does not have a second electron affinity because adding an additional electron to selenium would require more energy to overcome the repulsion between the negatively charged electron and the negatively charged selenium ion. In other words, the energy required to add a second electron to selenium is higher than the energy released in the process.
The energy released on adding an electron to an isolated gas phase atom is called electron affinity. It represents the willingness of an atom to accept an additional electron. The process can release energy if the atom's electron affinity is negative, indicating that the atom is stable after gaining an electron.
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
The highest energy electron in uranium is found in the 5f subshell. Uranium has 92 electrons, so the configuration for the highest energy electron would be [Rn] 5f³ 6d¹ 7s².
Ionization energy would be similar.
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.