Question

The M shell of an atom contain 7 electrons a) Write electronic configuration b) Write the atomic number c) Write number of electrons​

Answer 1

Electronic configuration of shell M contains 7 electrons

Explanation:

• According to question, an atom has M shell which contains 7 electrons i.e. third shell has 7 electrons. An atom has K, L, M, N and so on shells.      

         K shell has electrons    = 2

        L shell has electrons     = 8

         M shell has electrons    = 8     and so on

• So, this atom has 2 electrons in K shell, 8 electrons in L shell and 7 electrons in M shell.
• Hence, electronic configuration of given atom is 2, 8, 7.
• Therefore, it's atomic number is 17 i.e. it is Chlorine.
• We known, Atomic number = number of protons = number of electrons thus, number of electrons in given atom is 17.