Please let know how is Electronegativity value in Halogen family? I am really unclear. Thank you.

2 Answers
Oct 26, 2016

The electronegativity values for the VIIA group or Halogen value are the highest in their period or row, and decrease as the atomic number of the Halogen increases.


The group VIIA or Halogens have a valance electron configuration of #ns^2 np^5# where n is the period number of the row where the element is found.

This gives the Halogens 7 valance electrons. One more electron will give the Halogens the same electron configuration of the VIIIA group also called the noble or inert gases. Gaining that one more electron will cause the Halogen to achieve a great level of stability.

The electron configuration causes the Halogens to have a strong pull for one more electron. The definition of electronegativity is the pull of the element for more electrons. Thus the VIIA or Halogens will have the highest electronegativity of any element in their row, or period.

Florine number 9 #F_9^19# has the highest electronegativity of any element in the periodic table at 4.0. As the smallest of the Halogens it has the greatest pull for electrons as there is less electron shedding by other shells of electrons.

The electronegativity of the Halogens decreases as the elements get larger and therefore less reactive.

Nov 10, 2016

Here are the electronegativities of the halogens.


#"F" = color(white)(l)3.98#
#"Cl" = 3.16#
#"Br" = 2.96#
#"I" = color(white)(ll)2.66#
#"At" = 2.2#

Below is a diagram of electronegativity trends in the Periodic Table.

Electronegativity trends

The trends for the halogens (in Group 17) are shown by the yellow arrow.

The electronegativities increase from the bottom to the top of the Group, and #"F"# is the most electronegative atom in the Periodic Table.

Electronegativity tends to increase from left to right in a Row of the Periodic Table.

With the exception of astatine (in Row 6), each halogen has the highest electronegativity of any element in its Row.