Bonding · Topic 5 of 15

Chemical Bonds & Intermolecular Forces

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Chemistry · bonding

Chemical Bonds & Intermolecular Forces

Ionic bonds transfer electrons and covalent bonds share them; unequal sharing makes polar molecules like water, which attract each other through hydrogen bonds.

01 · IonicIonic = electrons transferred

02 · CovalentCovalent = electrons shared

03 · WaterWater: bent and polar (O δ−, H δ+)

What it is

Ionic bond: electrons transferred (metal → nonmetal); + and − ions attract must know

Covalent bond: electrons shared, usually between nonmetals (H₂O, CH₄) must know

Water is bent and polar: oxygen end δ−, hydrogen ends δ+ must know

Forces between molecules: hydrogen bond > dipole–dipole > London dispersion must know

London dispersion: temporary dipoles, in all molecules, stronger in bigger ones

Dipole–dipole: δ+ end of one polar molecule pulls the δ− end of another

Hydrogen bonds give water high specific heat, cohesion and floating ice

Single bond = 1 shared pair · double = 2 pairs · triple = 3 pairs

The rules

Hydrogen bond: H on N, O or F pulled toward N, O or F of another molecule

Stronger forces between molecules → higher melting and boiling points

Electronegativity gap: ~0 nonpolar · moderate polar (H–Cl) · large ionic (NaCl)

Don't confuse

Nonpolar bond: equal sharing (H₂) · polar bond: unequal, δ− on the stronger puller must know

Ionic or covalent?

Commonly confused

	Ionic bond	Covalent bond
Electrons	Transferred	Shared
Usually between	A metal and a nonmetal	Two nonmetals
Particles formed	Oppositely charged ions	Molecules
Electronegativity gap	Large (Na–Cl 2.1)	Zero to moderate (H–H 0, H–Cl 0.9)
Examples	NaCl (table salt)	H₂O, CH₄, H₂

Common mistakes

Trap: a hydrogen bond is a pull between molecules, not a covalent bond

Polar bonds + symmetric shape = nonpolar molecule (CO₂); bent H₂O stays polar

More detail

Show 4 more facts

Like dissolves like: water dissolves polar and ionic substances, not oils

Ionic solids: brittle, high melting point, conduct only melted or dissolved

Hydrogen bonds hold DNA's two strands together

Bonds formed ≈ electrons needed for an octet (carbon: 4 bonds)

Pearl

Ionic bonds give electrons away; covalent bonds share them.

Sources · OpenStax Chemistry 2e §7.1 Ionic Bonding · OpenStax Chemistry 2e §7.2 Covalent Bonding (polarity and electronegativity) · OpenStax Chemistry 2e §7.3 Lewis Symbols and Structures (single, double, triple bonds; octet rule) · OpenStax Chemistry 2e §7.6 Molecular Structure and Polarity · OpenStax Chemistry 2e §10.1 Intermolecular Forces · OpenStax Biology 2e §2.2 Water · Union Test Prep — HESI Chemistry study guide, page 2 (chemical bonding, bond polarity, intermolecular forces) · TSTC Library — HESI A2 guide (Chemistry list: shared vs transferred electrons; properties of water) · Built from the verified NurseSavvy HESI A2 fact map (facts reviewed 2026-10-16). HESI is a trademark of Elsevier; NurseSavvy is not affiliated with Elsevier.

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