Chemical Bonding
Understand why and how atoms bond together with this essential chemical bonding flashcard deck. Chemical bonding is the foundation of molecular chemistry — mastering it explains the properties of every substance you encounter, from water to DNA to metals. This deck covers ionic bonding, covalent bonding (polar and nonpolar), metallic bonding, Lewis dot structures, electronegativity and bond polarity, VSEPR theory and molecular geometry, hybridization, and intermolecular forces including hydrogen bonding, dipole-dipole interactions, and London dispersion forces. Essential for AP Chemistry, GCSE, A-Level, and university general chemistry courses.
All Cards in This Deck
Question
What is a chemical bond?
Answer
A force of attraction that holds two or more atoms together. Bonds form when atoms achieve a more stable (lower energy) arrangement, usually by completing their outer electron shell.
Question
What is an ionic bond?
Answer
A bond formed by the transfer of electrons from a metal to a nonmetal, creating oppositely charged ions (cation + anion) that attract each other. Example: Na⁺Cl⁻ (table salt).
Question
What is a covalent bond?
Answer
A bond formed by the sharing of electrons between two nonmetal atoms. Both atoms achieve a full outer shell by sharing. Example: H₂, H₂O, CO₂.
Question
What is the difference between polar and nonpolar covalent bonds?
Answer
Polar: Electrons shared unequally because atoms have different electronegativities (e.g., H₂O, HCl). Nonpolar: Electrons shared equally between identical or similar atoms (e.g., H₂, O₂, CH₄).
Question
What is a metallic bond?
Answer
Bonding in metals where positively charged metal ions are surrounded by a "sea" of delocalized electrons. Explains metals' conductivity, malleability, and ductility.
Question
What are Lewis dot structures?
Answer
Diagrams showing valence electrons of atoms as dots around the element symbol. Used to visualize bonding and lone pairs in molecules. Each dot represents one valence electron.
Question
What is the octet rule?
Answer
Atoms tend to form bonds until they are surrounded by 8 electrons in their outer shell (like noble gases). Hydrogen is an exception — it only needs 2 electrons.
Question
What is a single bond, double bond, and triple bond?
Answer
Single bond: 1 shared pair (2 electrons) — e.g., H–H. Double bond: 2 shared pairs (4 electrons) — e.g., O=O. Triple bond: 3 shared pairs (6 electrons) — e.g., N≡N. Stronger and shorter as bond order increases.
Question
What is electronegativity and how does it determine bond type?
Answer
The tendency of an atom to attract shared electrons. Difference < 0.4 = nonpolar covalent. Difference 0.4–1.7 = polar covalent. Difference > 1.7 = ionic bond.
Question
What is VSEPR theory?
Answer
Valence Shell Electron Pair Repulsion theory — electron pairs around a central atom repel each other and arrange themselves to be as far apart as possible, determining molecular shape.
Question
What is the molecular geometry of water (H₂O)?
Answer
Bent (V-shaped). Central oxygen has 2 bonding pairs and 2 lone pairs. Bond angle ≈ 104.5°. Polar molecule due to asymmetric shape and O–H bond polarity.
Question
What is the molecular geometry of ammonia (NH₃)?
Answer
Trigonal pyramidal. Central nitrogen has 3 bonding pairs and 1 lone pair. Bond angle ≈ 107°. Polar molecule.
Question
What is the molecular geometry of methane (CH₄)?
Answer
Tetrahedral. Carbon has 4 bonding pairs, no lone pairs. Bond angle = 109.5°. Nonpolar molecule — symmetrical shape cancels out bond dipoles.
Question
What is the molecular geometry of carbon dioxide (CO₂)?
Answer
Linear. Carbon has 2 double bonds, no lone pairs. Bond angle = 180°. Nonpolar overall — polar C=O bonds cancel out due to symmetry.
Question
What is hybridization in chemistry?
Answer
The mixing of atomic orbitals to form new hybrid orbitals with different shapes and energies. sp³ (tetrahedral), sp² (trigonal planar), sp (linear).
Question
What is a hydrogen bond?
Answer
A strong intermolecular attraction between a hydrogen atom bonded to F, O, or N and the lone pair of another F, O, or N atom. Explains water's high boiling point and surface tension.
Question
What are London dispersion forces (LDF)?
Answer
The weakest intermolecular force — temporary dipoles caused by random electron movement attracting neighboring atoms/molecules. Present in ALL molecules. Stronger in larger, heavier molecules.
Question
What are dipole-dipole interactions?
Answer
Intermolecular attractions between the positive end of one polar molecule and the negative end of another. Stronger than London forces but weaker than hydrogen bonds.
Question
What determines the strength of intermolecular forces?
Answer
Stronger IMFs = higher boiling point, melting point, and viscosity. Order of strength: London forces < dipole-dipole < hydrogen bonds < ionic interactions.
Question
What is a coordinate (dative) covalent bond?
Answer
A covalent bond where both electrons in the shared pair come from the same atom. Example: NH₄⁺ (ammonium ion) — nitrogen donates both electrons to H⁺.
Question
What is bond length and how does it relate to bond order?
Answer
The distance between the nuclei of two bonded atoms. As bond order increases (single→double→triple), bond length decreases and bond strength increases.
Question
What is resonance in chemistry?
Answer
When a molecule cannot be represented by a single Lewis structure — the actual structure is an average (resonance hybrid) of multiple structures. Example: benzene (C₆H₆), ozone (O₃).
Question
What is a sigma (σ) bond vs a pi (π) bond?
Answer
Sigma bond: Head-on orbital overlap — forms first in any bond (all single bonds are sigma). Pi bond: Side-on orbital overlap — forms in addition to sigma in double and triple bonds.
Question
What makes water such an unusual molecule?
Answer
Bent shape + high electronegativity of O + 2 lone pairs create strong hydrogen bonds. This gives water an abnormally high boiling point, specific heat capacity, and surface tension.
Question
What is the difference between intramolecular and intermolecular forces?
Answer
Intramolecular: Forces within a molecule (chemical bonds — ionic, covalent, metallic). Intermolecular: Forces between separate molecules (LDF, dipole-dipole, hydrogen bonds). IMFs are much weaker.