Question

Explain the Halogens.

Answer 1

Halogens are the elements and part of the periodic table.Includes Fluorine, Chlorine, Bromine and Iodine. Atomic radius trend in the halogen on moving from fluorine to iodine and the reactivity is inversely proportional to the atomic radius and also electronegativity plays the role.

Complete answer:
In the lower classes of chemistry, we have studied about various trends in the periodic table which includes the trend in the ionisation energy, trend in the electronegativity, trend in the electron affinity and many other variations in the trend on moving across the periods and groups.
We shall now see what factors affect the reactivity halogens.
- Halogens are the six elements in the group 17 of the periodic table according to the IUPAC and normally in the group 7A.
- On moving down the group that is from fluorine to that of iodine, the atomic radius increases and iodine has a large atomic radius.
Due to the increase in the atomic radius, the attraction of the outer electrons towards the nucleus decreases and therefore, the reactivity trend of the halogens decreases.
- Another factor that relates to the reactivity is the electronegativity of the halogens. Electronegativity is the tendency to attract the shared pair of electrons and when we move from fluorine to iodine, the electronegativity decreases because there is less attraction of electrons.
This leads to the less reactivity of halogens on moving down the group.
Therefore based on these above facts, we can say that the order of reactivity of the halogens will be ${{F}_{2}}$ > $C{{l}_{2}}$ > $B{{r}_{2}}$ >${{I}_{2}}$.

Note:
Note that the name halogen is given to these elements belonging to group 17 from the Greek word ‘hal’ which means salt and ‘gen’ which means to produce because halogens are those which produce salts of similar properties.