Example thrum (3): 1s22S Boron(5): 1s22522p' 111 2D Carbon(6): 1s22s22p2 2s Nitrogen(7 ): 1s22s22p3 Oxygen( 8): 1s22522p 1s The properties of an atom are determined mostly by its outermost electrons(最外层电子), since they are the ones in direct contact with the external environmentExample: Lithium (3): 1s 22s 1 Boron (5): 1s 22s 22p 1 Carbon (6): 1s 22s 22p 2 Nitrogen (7): 1s 22s 22p 3 Oxygen (8): 1s 22s 22p 4 The properties of an atom are determined mostly by its outermost electrons (最外层电子), since they are the ones in direct contact with the external environment