Question

Why are Group 17 elements very reactive?

Answer 1

• Elements from Group-17 in the periodic table are called halogens.
• They are Fluorine, Chlorine, Bromine, Iodine, and Astatine.
• They are called halogens because they are salt formers.

• All the elements from this group have 7 valence electrons in their outermost shell, and in order to gain stability and complete their octate, they tend to accept one electron.

$$\begin{gathered} {}_9\mathrm{F}\to 2,7 \\ {}_{17}\mathrm{Cl}\to 2,8,7 \end{gathered}$$

• And also they all have smaller atomic radii comparatively, which means they strongly attract electrons towards themselves; i.e., they are highly electronegative.
• Therefore, group-17 elements are highly reactive.