Question

What is the noble gas notation for Indium?

Answer 1

Hint: The modern periodic table displays us the various number of elements that are known up to till date. There are in total $ 118 $ elements which are known and represented in the periodic table. The notation of an element can be represented in terms of notation of its nearest noble gas by observing the electronic configuration of the element and configuration of the nearest noble gas element.

Complete Step By Step Answer:
Since we know that till now $ 118 $ elements are known and they are placed in the periodic table at their appropriate positions. Also there are $ 18 $ groups and $ 7 $ periods in the periodic table. Horizontal rows of elements refers to period while vertical column of elements refers to group. One such group is a group of noble gases. They are inert in the atmosphere. We will find the nearest noble gas close to the Indium element. The atomic number of indium is $ 49 $ . The first element of noble gas is helium whose atomic number is $ 2 $ . Other noble gases in increasing order of atomic number are: Neon $ (10) $ , Argon $ (18) $ , Krypton $ (36) $ , Xenon $ (54) $ , and Radon $ (86) $ . Xenon and Radon are radio-active in nature. Therefore the nearest noble gas to indium is Krypton whose atomic number is $ 36 $ . Thus the difference in the number of electrons in krypton and indium is $ 49 - 36 = 13 $ . Hence Indium has thirteen more electrons than Krypton. We can write electronic configuration of each element as:
For Krypton $ (36) $ ,
 $ 1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^6} $
For Indium $ (49) $ .
 $ 1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^6}4{d^{10}}5{s^2}5{p^1} $
On comparing both electronic configuration we can write as:
Indium: $ Kr\left[ {4{d^{10}}5{s^2}5{p^1}} \right] $
Hence it is the noble gas notation of Indium.

Note:
Since the Indium element contains thirteen electrons more than the Krypton element which can be seen in the electronic configuration also. If this difference of electrons is not visible in electronic configuration then there is some error while writing the notation. The electronic configuration written above is in increasing order of orbitals.