Question

what are the similarities in the properties of elements in halogen family

Answer 1

What Makes Them Similar? When you look at our descriptions of the elements fluorine and chlorine, you will see that they both have seven electrons in their outer shell. That seven-electron trait applies to all of the halogens. ... Fluorine is the most reactive and combines with most elements from around the periodic table.

Answer 2

all chemical properties like their chemical reaction with other elements, acidic behaviour, valency, their formula in a given compound etc are similar of all the elements of halogen group.

Simply we can say all the properties based on the valence electrons are same .Since in a group valence electrons is same so their properties will be same.

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