Answer :
Answer: Aluminum must lose 3 electrons since it is a cation.
Explanation: Aluminum has 13 electrons arranged in three orbitals. The first orbital shell has 2 electrons. Second shell contains 8 electrons and the third shell has 3 electrons.
Since aluminum is a cation it must lose its 3 valence electrons to become stable having an octet in the second shell which have 8 electrons.