Question

For a sodium atom, the outermost orbit containing electrons is the
1- first orbit
2- second orbit
3- third orbit
4- fourth orbit​

Answer 1

3rd orbit

How?

• Sodium has Atomic number(Z)=11

Let's look at Electronic configuration of Sodium

$\\ \sf\longmapsto 1s^22s^22p^63s^1$

Final orbital is 3s .

Hence proved