Polonium has the lowest electron affinity in the oxygen family.
Ununtrium
thalium
Francium
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).
3) Sodium
Potassium is the group 1, period 4 element on the periodic table. That means that its electron configuration is 1s2 2s2 2p6 3s2 3p6 4s1. This can be shortened to [Ar] 4s1 because argon's electron configuration is 1s2 2s2 2p6 3s2 3p6.
A valence electron, or valence electrons, are found in all of the elements. A valence electron is an electron located on the out most shell of an element (the valence shell). Most elements will have more than one valence electron. Oxygen, or O, has six valence electrons because its outer shell consists of six electrons.
The number of electrons in a neutral atom of any element is the same as the number of protons in the nucleus of the atom. The number of protons in an element is the same as the atomic number for that element. In the case of Gold (Au) the atomic number is 79.
No, nitrogen does not have a low electron affinity. Electron affinity increases as you go up and to the right on the periodic table. Thus, Groups I and II elements (ex. Cs, Ba, Sr, etc.) have LOW electron affinities and the halogens in Group VII (Br, Cl, F, etc) have the HIGHEST electron affinities. Chlorine has the HIGHEST electron affinity on the periodic table.(Fluorine is an exception in this case.)
The halogen with the least-negative electron affinity is astatine. Electron affinity and electronegativities decreases down a group. Since astatine is the last halogen located in Group 17 as you move down the column from fluorine, it has the least negative electron affinity.
Down the group electron affinity decreases Across a period electron affinity increases. However, it should be noted that chlorine is having higher electron affinity than flourine due to the small size of fluorine atom)
The group that has a substantial affinity for electrons is group 17, the halogens. These elements have 7 valence electrons which makes them have the highest affinity for electrons.
Groups 6 and 7.
As you go across a period; Left to right, the electron affinity increases. As you go down a group; top to bottom, the electron affinity decreases.
The outer electrons in bigger halogens are further from the nucleus and so they feel less attraction and so are easier to remove. Therefore, astatine has the lowest ionisation potential of the halogens.
decreases from top to bottom
Group 8A, the noble gases because they have high electron affinity.
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).
The electronegativity increase in a period from left to right; in a group decrease by descending.
That element would be in the Alkali Metals (group one)