(magnesium oxide), Ca 2+ Cl 2 so Na 2 C0 3 ) N a Mg A I Si P S Cl Ar 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge AS Se Br Kr 5 fib Sj Y Zr m Mo Tc Hu Rh Pd Ag Cd In Sn Sb Te 1 Xe 6 Cs Ba La HI Ta w Re Os Ir Pt Au Hg TI Pb Bi Po At Rn 7 Fr Rd AC Large Radii 3 Ci