because of having only one electron in valence shell
halogens.
The halogens are the most reactive nonmetals. They belong to Group 17 on the periodic table.
halogens
The Halogens are the most reactive non-metals. However, their reactivity decreases as you go down the group. Most reactive Fluorine>Chlorine>Bromine>Iodine>Astatine Least reactive. However, Astatine is not fully characterised because it is radio-active, and consequently is not found in open(school) labs.
Metals: alkaline metals Nonmetals: halogens
The most reactive nonmetals are the Halogens. They are located in the second to last row on the Periodic Table from the right.
Group 17 (known as Halogens)
Halogens among halogens fluorine is most reactive
Halogens
Halogens
The halogens are the most reactive class of nonmetals due to their high electronegativity and tendency to gain electrons to achieve a stable electron configuration. This results in them readily forming compounds with other elements.
The halogens are the most reactive family of nonmetals, as they have a strong tendency to gain an electron to achieve a full outer shell. Among metals, the alkali metals are the most reactive due to their low ionization energy and strong tendency to lose an electron to achieve a stable electron configuration.