In discussing halogen reactivity (as covered in Core Idea), it is a common practice to argue that as you go down the Group 17 elements it becomes harder for the elements to gain an electron to form a ...

The periodic table The periodic table is a chart of all ... all react vigorously with water to produce an alkaline solution. Group 7 halogens The Group 7 elements are also known as the halogens.

The element is known as Tennessine (Ts), number 117, and is classified as a halogen. "Taking a seat at the periodic table didn't happen overnight; it was a 20-year journey," she said in an ...