Put the elements in order from the highest electronegativity at the top of your list, to the lowest at the bottom.swap_vertFluorine (F)swap_vertBoron (B)swap_vertCarbon (C)swap_vertOxygen (O)swap_vertSodium (Na)

Answer
The electronegativities ranked from high to low order
1. Fluorine
2. Oxygen
3. Nitrogen
4. Carbon
5. Boron
6. Sodium
The electronegativities increases from left to right of your periodic table.
Explanation
Electronegativity of:-
Fluorine = 3.98
Boron = 2.04
Carbon = 2.55
Oxygen = 3.44
Sodium = 0.93
Nitrogen = 3.04