Question

Write electronic configuration of the elements (number in the brackets indicate atomic numbers)
Potassium (19)

Answer 1

In order to write the electron configuration of Potassium, we first need to know the number of electrons for the Potassium atom. There are 19 electrons. When we write the configuration and for that, we have to put all 19 electrons in orbitals around the nucleus of the Potassium atom.

Complete answer:
Potassium, the 19th element on the periodic table. So, the atomic number for potassium is 19, which means there are 19 protons in the nucleus. In a neutral atom, the number of electrons is equal to the number of protons. Therefore, we can say that K also has 19 electrons. It has the electronic configuration of 2,8,8,1.
In writing the electron configuration for Potassium the first two electrons will go in the 1s orbital. Since 1s can only hold two electrons the next 2 electrons for Potassium go in the 4s orbital. The next six electrons will go in the 2p orbital. The p orbital can hold up to six electrons. We'll put six in the 2p orbital and then put the next two electrons in the 3s. Since the 3s are now full we'll move to the 3p where we'll place the next six electrons. We now shift to the 4s orbital where we place the remaining electron. Therefore, the electron configuration of Potassium will be:
$1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}4{s^1}$

Note:
Electron configuration contains all of the electrons consecutively, with the period number, type of orbital (s, p, d, f) and the number 1 or 2 representing whether it is the first or second electron in that orbital.