Question

How many valence electrons does sodium have?

Answer 1

1. bc valence electrons are the amount of electrons on the outer shell of the bohr model. if you look at the periodic table from left to right they are numbered 1-8 the columns. this stands for the valence electrons, sodium's being 1

Answer 2

Sodium has one valence electron

Valence electrons are the outermost electrons, and are the ones involved in bonding. Sodium has 11 electrons: its atomic number is 11, so it has 11 protons. Atoms are neutral, so this means that sodium also has 11 electrons

Electrons are arranged in shells or energy levels.
The first evel can have 2 electrons; 
The second level can have up to 8 electrons.
The third level can have up to 8 electrons as well

So, sodium´s 11 electrons are arranged this way - 2 electrons in the first shell or level; 8 electrons in the second level; and 1 electron (the valence electron) in the third level.

The correct way to write this is 2.8.1 - The last number is how we know the number of valence electron.