Question

Name two elements which will be chemical similar to aluminum. What is the basis of your choice?

Answer 1

Aluminum is the element of group $13$. The periodic table is structured in the way that the elements in the same column will have similar valence structures and therefore similar chemical properties as aluminum.

Complete answer:
Aluminum is the first element of group $13$. The other elements of this group are $B,Ga,In,Th$ and $Nh$. The periodic table of the element suggests two elements that have almost the same chemical properties of aluminum. They are gallium $(Ga)$ and indium$(In)$. Their oxidation number including aluminum is $3$
Chemical properties of aluminum: When it comes in contact with oxygen, aluminum forms an oxide skin called aluminum oxide. This skin helps to protect aluminum from corrosion. Aluminum catches fire easily if exploded to flame when it is in powdered form, it is also reactive with both acid and base. When combines with elements such as copper, silicon or magnesium it forms alloys of great strength
Their valencies are $+ 3$. The electronic configurations are:
Aluminum: $[Ne]3{s^2}3{p^1}$
Gallium: $[Ar]3{d^{10}}4{s^2}4{p^1}$
Indium: $[Kr]4{d^{10}},5{s^2},5{p^1}$
Though the two elements have almost similar chemical properties to aluminum they do not have the same chemical properties as aluminum.

Note:
Elements in a group generally have similar properties because their electronic configuration is similar. The best group that can highlight these similarities is group $18$ (the Noble gas). All elements in group $18$ are gases at most temperatures, have completely filled electron shells, are usually non reactive, and form compounds only in extreme circumstances.