Column tells you how many valence electrons there are
Row tells you how many layers (circles)
Sodium (Na) has 1 valence electron
Sodium (Na) is the 3rd row so there's 3 circles
Has 11 total electrons
Bohr models show ALL ELECTRONS
The first shell can only hold 2 electrons
Every shell after that can hold 8.
So the first shell has 2 electrons, second one has 8 electrons, and the third one has 1.
2 + 8 + 1 = 11
Row tells you how many layers (circles)
Sodium (Na) has 1 valence electron
Sodium (Na) is the 3rd row so there's 3 circles
Has 11 total electrons
Bohr models show ALL ELECTRONS
The first shell can only hold 2 electrons
Every shell after that can hold 8.
So the first shell has 2 electrons, second one has 8 electrons, and the third one has 1.
2 + 8 + 1 = 11