Berylium has 2 outer shell electrons. I say this because berylium has an atomic number of 4. When arranging the electrons, which are also 4, 2 electrons go to the first shell to complete it. The next shell needs 8 electrons to be completed. So only 2 electrons go there, and since it is not complete in order to form another shell, it is the outer shell. And it has 2 electrons. Hope i helped. Have a nice day.