Why do transition metals show a lot of chemical similarities within a given period? September 21, 2022 by 8i9x6 The valence s and p electrons affect their chemistry more so than the inner d and f electrons,which do not participate in bonding as easily. The number of electrons within a given period varies only slightly and is sometimes identical because these metals have more than one ionic form. All elements in a given period,including the representative elements,have a lot of chemical similarities due to the gradual increase in atomic number. The transition metals always fill their s and p orbitals first before filling their d orbitals,which affects their chemistry. None of the above is correct. See Answer The valence s and p electrons affect their chemistry more so than the inner d and f electrons,which do not participate in bonding as easily.