1s 2s 2p 3s 3p 3d 4s Electronic configuration: FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He 1s 1 Ne Ar Kr Hydrogen 1 2 GROUP Li Al B

Helium 1s 2s 2p 3s 3p 3d 4s Electronic configuration: 1s 2 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s Electronic configuration : 1s 2 Lithium 2s 1 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s Electronic configuration : 1s 2 Beryllium 2s 2 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s Electronic configuration : 2p 1 Boron 2s 2 1s 2 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s Electronic configuration : 1s 2 Carbon 2s 2 2p 2 The next electron does not pair with the first electron in 2p, but occupies the empty box (orbital) to keep them as far apart as possible. FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s Electronic configuration : 1s 2 Nitrogen 2s 2 2p 3 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s Electronic configuration : 2p 4 Oxygen 2s 2 1s 2 Now that all 3 p orbitals are filled the next electron must pair up. FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s Electronic configuration : 1s 2 2s 2 2p 5 Fluorine FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

Neon 1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 1 Sodium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 Magnesium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 1 Aluminium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 2 Silicon FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 3 Phosphorus FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 4 Sulphur FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 5 Chlorine FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

Argon 1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 1 Potassium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 2 Calcium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 2 3d 1 Scandium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2 Titanium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 2 3d 3 Vanadium FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

Chromium 1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 1 3d 5 Notice that one of the 4s electrons has been transferred to 3d so that 3d is now a half filled shell with extra stability. 4s and 3d contain only unpaired electrons. FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 3d 5 Manganese 4s 2 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

Iron 1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6 FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 2 3d 7 Cobalt FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 2 3d 8 Nickel FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 4s 1 3d 10 Copper Notice that again one of the 4s electrons has been promoted to 3d so that 3d is now a completely filled shell with extra stability. FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

1s 2s 2p 3s 3p 3d 4s 1s 2 Electronic configuration: 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 Zinc FeMnVTiScK Na ZnCuNiCrCo Mg Ca Be H As O S Se F Cl BrGa C Si Ge N P He Ne Ar Kr 1 2 GROUP Li Al B

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