How do you figure out the # of electrons per layer when creating a Bohr model?

Electrons = Protons and protons = Atomic number





so hydrogen has 1 proton 1 electron on the first layer





Aluminum is 13 its layers would be





2-8-3





The first layer of an atom always holds 2 electrons. Period.


Every layer after that holds 8 until we reach the last layer. A layer needs 8 electrons in it to move on to the next level.How do you figure out the # of electrons per layer when creating a Bohr model?
There's a basice trend to the Bohr model. The first level has just two electrons. The second can have 8. The third can also have 8. The fourth can have up to 18. Just look at your periodic table. It's pretty much modeled after the way an atom has its electrons. The first level is the same as the first shell. There are two elements so there can be two electrons.