Question

Why is hydrogen called a rogue element in the periodic table?

Answer 1

It has some special characteristics that behave different from other elements in the periodic table. And hydrogen element do not have a fixed position in the periodic table. These are the reasons why hydrogen is called as a rouge element.

Answer 2

hydrogen is termed as a rogue element in the periodic table as it behaves like alkali metal, have one valence electron and can form halides and also have properties of halogens also, gives H- when gains an electrons. Hence, its postion is not fixed in the periodic table and is therefore termed as rogue element in the periodic table.