The number in the periodic table that tells the number of valence electrons is the group number that we can see above the columns. 
1 5 1
what kind of element has less than 4 valence electrons??
metals po
ang more than po??
non-etals po
okay salamat
The family no. if the family number for example is IIA it means that the element has two valence electrons and the orbital that corresponds to the valence electrons is either S orbital or P orbital, in IIB, the element has still two valence electrons but the orbital is either the D or F orbital