Hello there,

Group of 17 elements is also known as halogens. That means they are the group of elements which are highly reactive nonmetals and capable of forming salts. All these elements are representative and belong to the p-block of the periodic table.

They exist as diatomic molecules, exhibit decreasing reactivity down the group, and show a change in physical state from gas to liquid to solid at room temperature, with increasing boiling points and densities.

Here is the link attached from the official website of Careers360 which will provide you with detailed characteristics of Group 17 elements. Kindly go through this.

https://www.careers360.com/chemistry/group-17-elements-halogen-family-topic-pge

thank you!