Replace the reactant specified in each of the following compounds with another element based on periodic properties of the periodic table. Justify each answer using the electron configurations of the elements.

a. Replace Al in Al + O2 → Al2O3.

b. Replace Br in Be + Br2 → BeBr2.

I have no idea how to do this. Any help would be appreciated .

Question

Replace the reactant specified in each of the following compounds with another element based on periodic properties of the periodic table. Justify each answer using the electron configurations of the elements.

a. Replace Al in Al + O2 → Al2O3.

b. Replace Br in Be + Br2 → BeBr2.

I have no idea how to do this. Any help would be appreciated .

ookawaiioo · Answer

Pick an element below or above Al and Br on the periodic table. 

Column of element have similar chemical reactivity. 

For example: Oxygen and sulfur have similar reactions

anonymous · Answer

@oOKawaiiOo Thanks for the reply. So in this case, I can replace Al with Ga in the first problem and Br with I in the second problem? Also, how can I justify this with each elements electron configuration? For example, Al has 13 electrons whereas Ga has 31, so their respective configurations would be quite different. Therefore, how can I justify it with their configurations if they are so different?

ookawaiioo · Answer

Its the number of valence electrons that are the same. 

They can be diff in atomic radii .