Aneutral atom possesses an atomic number of 13 and an atomic mass of 27. three electrons are lost. from what region of the atom are they lost?

a)outside the atom

b)outside the nucleus

c)inside the nucleus

d)both inside and outside the nucleus

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!