Question

19. An atom has electronic configuration 2,8,7.​

Answer 1

Answer:

Explanation:Solution: As the electronic configuration of the given atom is 2,8,7 it is inferred that the atomic number of element is 17 (2+8+7). Thus element with atomic number 17 is Chlorine. Among the options given which includes Nitrogen, Fluorine, Phosphorus and Argon, chlorine is chemically similar to fluorine.

Answer 2

Answer:

the element is Chlorine. Symbol is Cl. No of Valence electron is 7. Valency is 2. Charge is -2. Belongs to 17 th group and to 3rd period. It is a halogen.