Why are group 17 elements highly reactive?

Hint : The periodic table is a table that lists all of the chemical elements in order of atomic number, starting with hydrogen and ending with oganesson. The number of protons in the nucleus of an atom of a given element is its atomic number. The difference between hydrogen and oganesson is that hydrogen has one proton and oganesson has $ 118 $ .

Complete Step By Step Answer:
Any of the six non-metallic elements that make up Group $ 17 $ (Group VIIa) of the periodic table is halogen. Fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Tn) are the halogen components (Ts). Since they all contain sodium salts with similar properties, they were given the name halogen, which comes from the Greek roots hal- (“salt”) and -gen (“to produce”). The most well-known of these sodium salts is sodium chloride, also known as table salt or halite.
On the periodic table, the halogens are to the left of the noble gases. Since halogen elements have seven valence electrons, they only need one more electron to complete an octet. Because of this, they are more reactive than other non-metal groups.

Note :
Uses of halogen. Chlorine is a chemical that is used to purify water. Chlorine is also found in salt, sodium chloride, one of the most commonly used chemical compounds. Fluoride is a chemical that is applied to drinking water to avoid tooth decay.