Answer: [tex]Cl:17:[Ne]3s^23p^5[/tex]
[tex]Se:34:[Ar]3d^{10}4s^24p^4[/tex]
[tex]Te:52:[Kr] 4d^{10}5s^25p^4[/tex]
Explanation:
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.
The electrons are filled according to Afbau's rule in order of increasing energies and thus the electronic configuration in terms of noble gas configuration is:
a) Cl is an element with atomic number 17 and thus contains 17 electrons with Ne as nearest noble gas with 10 electrons
[tex]Cl:17:[Ne]3s^23p^5[/tex]
b) Se is an element with atomic number 34 and thus contains 34 electrons with Ar as nearest noble gas with 18 electrons
[tex]Se:34:[Ar]3d^{10}4s^24p^4[/tex]
c) Te is an element with atomic number 52 and thus contains 52 electrons with Kr as nearest noble gas with 36 electrons
[tex]Te:52:[Kr] 4d^{10}5s^25p^4[/tex]