Answer:
Option c, Mg and F
Step-by-step explanation:
Let's think this question.
a. Nitrogen and Sulfur. They make a covalent bond to form N2S3. They are both non metallic.
b. Na and Al, it is impossible for two metals to make a ionic compound
d. O and Cl also are joined by covalent bond to form Cl2O3. They are both non metallic.
C is the best choice. A non metallic and a metallic element usually makes a ionic compound. It can be assured by the EN (Pauling Rule). We should substract EN (data in periodic table)
ΔΕΝ = EN F - EN Mg
ΔΕΝ = 4 - 1.2 = 2.8
This is absolutely a ionic compound
If ΔΕΝ > 1.7, it is a ionic bond
If 0.4 < ΔΕΝ > 1.7 it is a polar covalent bond
If ΔΕΝ < 0.4 it is a non polar covalent bond