SCI 9 PPT QUANTUM Mechanical Model of an Atom.pptx

Science 9 Elements

1. Aufbau Principle

2. PAULI EXCLUSIONPRINCIPLE For Example consider Li atom which has 3e –  to be arranged properly. let us assume the following configuration. ( i ) 1s 3  ( wrong configuration) (ii) 1s 2 , 2s 1 ,…etc. ( Correct configuration) No two electrons are found to have identical set of four quantum numbers and so 1s 2 ,2s 1  is the accurate electronic configuration of Li.