Practice question · Sort into groups
Sort each bond by its character, using electronegativity differences (ΔEN).
Groups: Nonpolar covalent · Polar covalent · Ionic
- Cl–Cl (ΔEN = 0)
- H–Cl (ΔEN ≈ 0.9)
- C–H (ΔEN ≈ 0.4)
- Na–Cl (ΔEN ≈ 2.1)
- H–O (ΔEN ≈ 1.4)
Hints
- Rough cutoffs: ΔEN below ~0.5 shares evenly; ~0.5–1.7 shares unevenly; above ~1.7 the electron is effectively transferred.
- Bonding is a continuum of electron tug-of-war, the categories are landmarks, not walls.
Show the answer
Nonpolar covalent: Cl–Cl (ΔEN = 0), C–H (ΔEN ≈ 0.4)
Polar covalent: H–O (ΔEN ≈ 1.4), H–Cl (ΔEN ≈ 0.9)
Ionic: Na–Cl (ΔEN ≈ 2.1)
Why
ΔEN measures how unevenly the bonding electrons are shared: even (nonpolar), lopsided (polar), or captured (ionic). C–H’s near-evenness is why oils repel water; H–O’s lopsidedness is why water dissolves salt.
Practise Bonding and molecular geometry
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