One can look to the periodic table for the atom’s symbol ... elements (group A), the group number is the same as the valance electron number. The transition metals (group B) are not usually ...

1s2 2s2 2p6 3s2 3p3 - phosphorous has vacant 3d orbitals that can be used in bonding - 'expanded valence shell ... Learning outcome: using the Periodic Table to explore underlying electron structre to ...

The electron configurations of the 3rd period d-block elements ... the 4s orbitals are in fact higher in energy than the 3d orbitals and the valence electrons are in the 4s orbtial.This raises another ...