Question

observe the modern periodic table and explain the gradstion in reactivity of halogen family st

Answer 1

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As studying the Modern periodic table, The group 17 contains the members of the halogen family.

All of them have the general formula X2. A gradation is observed in their physical state down the group.

Thus, fluorine (F2) and chlorine (Cl2) are gases. Bromine (Br2) is a liquid while iodine (I2) is a solid.

The elements in the group seven of the periodic table are termed as Halogens. The elements in this group are diatomic in nature and very much reactive. They are believed to be highly reactive with alkali metals and other metals.

One of the reasons for these elements being highly reactive is that they possess high electro negativity. They also possess nuclear charge that is highly effective. They can easily gain electrons.  

Within this group, Fluorine is considered to to be highly reactive. The moment you move down the group the electro negativity decreases as the size of the atom increases. The sharing electrons move further away from the nucleus and so does its attraction power decrease.