Answer:
only thing close I can see would be aluminun
Explanation:
atomic number of 13 and 8 2nd electrons in its shell.
Water, lower, and I'm not too sure for the third one... sorry.
Answer:
n=1 holds two electrons and n=2 holds eight electrons.
Explanation:
Hello
In this case, since the atomic number of aluminum is 13, its electron configuration is:

In such a way, we can see that the level n=1 is filled with two electrons since the subshell s is able to hold two electrons and the level n=2 is also filled but with eight electrons as s holds two whereas p holds 6. Moreover, n=3 is holding three electrons.
Best regards.
The amount if protons is the same as the amount of electrons, so it would be 8. The charge is -2. Look at oxygen in the periodic table.