Question

aluminum has 13 electrons. how many electrons are found in the outermost energy level for this atom which energy level is the outermost

Answer 1

Those electrons would be called valence electrons. Check the group number. 3 would be the amount in the outermost shell, so those are the valence electrons. 

Answer is 3 

Answer 2

The outermost energy level of an element are called the valence shell, that holds the valence electrons. they consist of  the highest energy level. In aluminum, the valence electrons are 3.