Why is Fluorine in the group 7 of the periodic table? Which element, Fluorine or Chlorine, has a higher electronegativity? Explain your answer.

Group 7 of the periodic table contains all the elements known as halogens. They all have 7 valence electrons (hence group 7!) in their outer shell (insert diagram or prop to show what the outer shell signifies).Fluorine has a higher electronegativity than Chlorine because it has one shell less than Chlorine. Hence, this means that any large molecule that will come near Fluorine will be largely attracted by its positive nucleus. The fact that Chlorine has one more shell means the positive nucleus is more shielded from any molecule that will come near it.