Question

how many electrons does aluminum need to gain to obtain a noble gas electron configuration?

Answer 1

take a look at a periodic table and count the blocks necessary, each block is 1 electron.

Answer 2

In addition to Aaronq's method, you can also use the group number. The ones of the group number is the number of valence electron the elements have. To obtain a noble gas electron configuration, an element will need to have 8 valence electrons.

Answer 3

Al tends to lose electrons, but if it needed to gain it would gain 5