Question

discuss the electonic configuration of argon(Z=18)and potasium(Z=19).

Answer 1

Z=18 is
1s 2 2s 2 2p 6 3s 3p 6
Z=19
Is 1s 2 2s 2 2p 6 3s 3p 6 4s 1

Answer 2

configuration of argon  whose atomic number is 18-
                                                                                   2,8,8 
 and configuration of potassium whose atomic number is 19 - 
                                                                                   2,8,8,1 ( as after fillling 8 electrons in the 3rd shell the 4th shell starts filling