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Types of Chemical Bonds

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Chemical bonds are not three separate boxes; they form a spectrum set by how evenly two atoms share their bonding electrons. The electronegativity difference (ΔEN) places a bond along it: near zero is nonpolar covalent, moderate is polar covalent, and large is ionic. Metals bond a fourth way, through a shared sea of electrons.

UNIT 2 TOPIC 2.1 • TYPES OF CHEMICAL BONDS BOND SPECTRUM Electronegativity difference (ΔEN) is a guide, not the only test. ΔEN ≈ 0 increasing ΔEN large ΔEN NONPOLAR COVALENT EXAMPLE: Cl₂ and C–H electrons shared nearly evenly; no permanent bond dipole Cl Cl symmetric electron cloud C–H bond is effectively nonpolar POLAR COVALENT EXAMPLE: HCl unequal sharing; the more electronegative atom carries δ− H Cl δ+ δ− lopsided electron cloud bond dipole points toward Cl IONIC EXAMPLE: NaCl electron transfer; separated ions attract strongly Na Cl [Na]⁺ [Cl]⁻ separated ions, strong attraction NO HARD CUTOFF ΔEN supports a claim, but element types and measured properties decide which bonding model applies. metal + nonmetal → often ionic BIG IDEA Greater ΔEN means a more uneven electron distribution and a larger bond dipole. more uneven as ΔEN increases TAKEAWAY Bonds are a continuum. ΔEN, element types, and measured properties together support the bonding claim. AP Chemistry · Unit 2 · Compound Structure & Properties
Bonding is a spectrum, not three boxes. As the electronegativity difference (ΔEN) grows, sharing goes from nearly even (nonpolar covalent) to lopsided (polar covalent) to essentially transferred (ionic). Metals are a separate case: a shared electron sea.
Bond Spectrum · Open the sandbox →

The traps here come from treating the spectrum as sharp categories: calling ionic bonding an all-or-nothing transfer, judging a bond from the elements' labels instead of their ΔEN, reading a tiny ΔEN as meaningfully polar, and lumping metallic bonding in with nonpolar covalent. The difference in electronegativity, not the element names, sets the character.

The work

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Lesson
Types of Bonds ›

Ionic, polar covalent, nonpolar covalent, and metallic sit on one continuum of electron sharing. The lesson reads ΔEN to place a bond, then closes with a ten-scenario check on where the boundaries actually blur.

Skill check · 10 scenarios
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Diagnostic
10-item topic check ›

Ten items spanning the four Topic 2.1 misconceptions: ionic bonding read as all-or-nothing, bond type judged from element labels, a tiny ΔEN called polar, and metallic bonding confused with nonpolar covalent.

Not started · 10 items · ~15 min
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Targeted Practice
Drill a single misconception ›

Pick one of the failure modes you missed and drill it on its own. The round is adaptive: two correct in a row clears the misconception and moves you to the next.

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