In the periodic table, electronegativities range from 0.7 for cesium, the smallest electronegative of the elements, to 4.0 for fluorine, the most electronegative.
Halogens are electronegative due to their high effective nuclear charge. Therefore they are very reactive and can absorb an electron by reacting with other elements.
Electronegativity. Electronegativity is a chemical property that describes the tendency of an atom or functional group to attract electrons.
Therefore, fluorine is the most electronegative element while francium is one of the least electronegative. (Helium, neon and argon are not listed on the Pauling electronegativity scale, but helium has the highest electronegativity on the AllredRochow scale.)
This trend shows that cesium has the lowest ionization energy and fluorine has the highest ionization energy (excluding helium and neon).
Electronegativity increases as you move from left to right on the periodic table. This is due to a higher charge on the nucleus, which makes the electron bond pairs very attracted to the atoms that are more directly on the periodic table. Fluorine is the most electronegative element.
Electronegativity is a measure of the atom’s ability to attract electrons when the atom is part of a compound. Since metals have few valence electrons, they tend to increase stability by losing electrons to become cations. Therefore, the electronegativities of metals are generally low.
Fluorine is more electronegative than chlorine. This is because fluorine is smaller than chlorine and therefore has a greater tendency to attract electrons.
Electronegativity of fluorine Fluorine is the most electronegative element as it has 5 electrons in its 2P shell. The optimal electron configuration of the 2P orbital contains 6 electrons. Because fluorine comes so close to the ideal electronic configuration, the electrons are kept very close to the nucleus.
Halogens are reactive because they want to capture the last electron to fill their outermost layer. If you look at the column of the periodic table, the atoms get bigger and have less ability to attract electrons. This makes the halogen astatine less reactive.
They are malleable, that is, deformable into plates, and ductile, that is, deformable into threads. They have high melting and boiling points and are all solid at room temperature with the exception of mercury (Hg), which is a liquid.
Fluorine is more reactive. This is because the valence / bond electrons in fluorine are closer to the nucleus than in chlorine and the like and are therefore more strongly attracted. Fluorine is the most electronegative and therefore the most reactive.
Scheele called the element deflogistic hydrochloric acid because chlorine had been known for 33 years. In 1807, Humphry Davy studied chlorine and discovered that it was a real element.