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 ...

and all the elements in group 0 are unreactive non-metals. The zigzag, staircase, line in the diagram of the periodic table above separates the metals, on the left, from non-metals, on the right.

As I’m writing this, I’m drinking coffee from my periodic table mug. This mug often prompts questions ... Then at the other extreme there are the gases and halogens. The idea that the table shows us ...

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 ...