Chapter 10 Modern Atomic Theory and the Periodic Table

the valence electron configurations for H ~ Ar• the valence electron configuration for theelement in each column is the same, but thenumber for the energy level is different• the chemical behavior and properties of elementsin a particular family are similar and must beassociated with the electron configurationabbreviated electron configurationB 1s 2 2s 2 2p 1 [He] 2s 2 2p 1Cl 1s 2 2s 2 2p 6 3s 2 3p 5 [Ne] 3s 2 3p 5Na 1s 2 2s 2 2p 6 3s 1 [Ne] 3s 1n = 4 K 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 [Ar] 4s 1Ca 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 [Ar] 4s 2element 21 ~ 30 transition elementselectrons are placed in the 3d orbitals14