Question 1
Multiple choiceEasy1 markThe electronegativity values, χ, of the elements in four binary compounds are shown.
| Element | Mg | O | Na | Cl | Ca | F | C |
|---|---|---|---|---|---|---|---|
| χ | 1.2 | 3.5 | 0.9 | 3.0 | 1.0 | 4.0 | 2.5 |
Which compound is predicted to have the greatest ionic contribution to its bonding?
Show answer and explanation
Answer: C [1]. A larger electronegativity difference indicates a greater ionic contribution. The differences are MgO: |3.5 − 1.2| = 2.3; NaCl: |3.0 − 0.9| = 2.1; CaF₂: |4.0 − 1.0| = 3.0; CF₄: |4.0 − 2.5| = 1.5. CaF₂ has the largest difference.
A: MgO has a substantial difference, but 2.3 is less than 3.0.
B: NaCl is ionic, but its difference of 2.1 is less than 3.0.
D: A high mean electronegativity alone does not indicate a greater covalent contribution; CF₄ is less ionic here because its electronegativity difference is smaller.
Remember: electronegativity difference indicates the ionic contribution to bonding.
Total: [1]