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
Answer: 0.37g
Explanation:avogadro number = 6.02214076x10^23 atoms/molecules per mole
a mole of Na2O = 2*23 + 16 = 52 g
4.25x10^21 atoms = 52*(4.25*10^21/6.02214076*10^23) = 0.37 g
Notice that the oxygen atom produced in the first step of this mechanism is consumed in the second step and therefore does not appear as a product in the overall reaction. Species that are produced in one step and consumed in a subsequent step are called intermediates.
I hope that helps
ps. not my words, my older cousins
They didnt have a powerfull enough microscope to see them an when they could they were moving to fast unless they were cold