Thanks Pauli
Friends I am electron, I have charge and mass, I am bound to atomic nucleus, Therefore I have properties quantum, Energy level(principal quantum number) , angular momentum(azimuthal quantum number) , magnetic quantum no, spin quantum no, As one more electron like me, is added to ones atom, That electron has to go to higher level, There will be greater angular momentum, Friends how may similar be two elements may be in terms of structure and form, No two elements will be same. All four quantum no of another electron added Will not be same as that of electron present in atom This is root of why we on earth have so many possibilities Of forming different types, of molecules and complex structures, Each new electro added to atom Have all four quantum numbers, But atleast one quantum no will be different. Compare to all the the electrons present in atom before it. Friends this is Pauli's Exclusion principle No two electrons in the same atom can have identical values for all four of their quantum numbers. Thanks Pauli sir for giving us a beautiful principle-Paulis Exclusion A root of maintaining diversity, biodiversity on Earth. Making life so unique and interesting on earth. Sukarma Thareja Alumnus IITK