Which of these is the correct lewis structure for a sodium atom

Explanation:

1. To draw the Lewis structure for the Na, first look in the periodic table the atomic number of the Na.

Atomic number of Na = 11

2. Find the electronic configuration of the Na:

As the Na has 11 electrons its electronic configuration will be:

3. As the level three of the Na has only one electron, it means that the sodium has only one valence electron and its Lewis structure will be represented as:

where the dot represents its valence electron.