Question

Chlorine : 2,8,7 : : fluorine : ............ correlation

Answer 1

Chlorine 2:8:7 :: Fluorine : 2:7

It is the electronic valency of  of the respective elements.

Explanation:

Chlorine 2:8:7 :: Fluorine : 2:7

It is the electronic configuration of the respective elements.  

• Chlorine and Fluorine are elements belonging to group 17. They are halogens, toxic and non-metallic elements.

• These are highly reactive elements when compared non-metallic elements. These elements have seven valence electrons, they only need one electron to achieve octet valency, hence are highly reactive.
• The boiling and melting points of elements increase down the group.
• The atomic number of Chlorine is 17 and the atomic number of Fluorine is 9

• The correlation is the electronic configuration of Chlorine is2:8:7 and Fluorine is 2:7