Carbon and Molecular Diversity of Life — Vocabulary Flashcards

Vocabulary flashcards covering key terms and definitions related to carbon, bonding, and carbon skeletons from the lecture notes.

Hydrogen

Valence = 1.

Oxygen

Valence = 2.

Nitrogen

Valence = 3.

Carbon

Valence = 4; can form covalent bonds with up to four other atoms.

Organic compounds

Carbon-based compounds—the chemistry of life.

Covalent bond

A bond formed by sharing electrons; carbon can form multiple covalent bonds with other atoms.

Big Four

Hydrogen, Oxygen, Nitrogen, and Carbon—the common partners in organic bonding.

Single bond

A covalent bond in which one pair of electrons is shared.

Double bond

A covalent bond in which two pairs of electrons are shared (C=C is common in unsaturated hydrocarbons).

Triple bond

A covalent bond in which three pairs of electrons are shared (rarer in simple hydrocarbons).

Methane

CH4; carbon single-bonded to four hydrogens.

Ethane

C2H6; two carbons single-bonded with a total of six hydrogens.

Ethene (Ethylene)

C2H4; carbon–carbon double bond; each carbon bonded to two hydrogens.

Molecular formula

Notation showing the numbers and types of atoms in a molecule (e.g., CH4, C2H6, C2H4).

Structural formula

Depicts the arrangement of atoms and bonds in a molecule (e.g., H-C-H for methane).

Ball-and-stick model

3D model with spheres for atoms and sticks for bonds.

Space-filling model

3D model showing relative sizes and packing of atoms.

Carbon skeleton

Backbone of an organic molecule formed by a chain of covalently bonded carbon atoms.

Straight chain

A linear, unbranched carbon skeleton.

Branched chain

A carbon skeleton with side chains branching off the main chain.

Ring (cyclic) skeleton

A carbon skeleton arranged in a ring (e.g., cycloalkanes, aromatics like benzene).

Double bond location

The position of a C=C bond in a skeleton can vary and affect structure.

Abbreviated structural formula

A simplified drawing that omits corner carbons and attached hydrogens.

Propane

C3H8; straight three-carbon chain.

Butane

C4H10; straight four-carbon chain.

Isobutane

Branched isomer of butane (2-methylpropane).

Cyclohexane

C6H12; six-carbon ring with single bonds.

Benzene

C6H6; six-carbon ring with alternating double bonds (aromatic).