What are the elements in the rightmost columns of the Periodic Table, as we face the Table?

1 Answer
Jun 1, 2017

Answer:

#"The halogens and the Noble Gases..........."#, i.e. #"Group 17 and Group 16."#

Explanation:

The halogens, fluorine, chlorine, bromine, iodine, are all non-metals. Astatine is so rare that its chemistry would be limited. The Noble Gases all have a complete valence shell, and are all gases under normal conditions.........