Question

An element has electronic configuration 2,8,7 i) To which group and period of the modern periodic table does it belong? ii) Is it metallic or non metalic and Why? iii) What is the atomic number of this element?​

Answer 1

(1)It belongs to Hallogen group
(2)And it is non-metal because non-metal contain 5,6,7 electron in their outermost shell.
(3) the atomic no. is (17)