Bonding and Water: Atomic Structure, Bond Types, and Emergent Properties flashcards

Vocabulary flashcards covering key concepts from the lecture notes: atomic structure, bonding (ionic, covalent, polar, nonpolar, hydrogen bonds), water properties, energy in chemistry, and foundational biology concepts like metabolism and emergent properties.

Atom

The basic unit of matter consisting of a nucleus (protons and neutrons) surrounded by electrons in orbitals; overall electrically neutral.

Nucleus

Center of an atom containing protons (positive) and neutrons (neutral).

Proton

Positively charged subatomic particle within the nucleus.

Neutron

Electrically neutral subatomic particle within the nucleus.

Electron

Negatively charged subatomic particle in the electron cloud surrounding the nucleus.

Electron cloud

Region around the nucleus where electrons are found, organized into shells and orbitals.

Electron shell

Layer around the nucleus where electrons reside; first shell holds 2 electrons, second and third shells hold more (as noted in lecture: second shell has 8 total electrons across 4 orbitals; third shell described similarly in context).

Orbital

Region within a shell where an electron is likely to be found; each orbital can hold up to 2 electrons.

Bohr model

Atomic model describing electrons in discrete shells around the nucleus (named after Niels Bohr).

Valence shell

Outermost electron shell of an atom; its full occupancy drives chemical bonding and stability.

Electronegativity

Tendency of an atom to attract shared electrons in a bond; differences between atoms determine bond type.

Electronegativity difference

Difference in electronegativity between two atoms; large differences favor ionic bonding, moderate differences yield polar covalent bonds, small differences yield nonpolar covalent bonds.

Ionic bond

Bond formed by transfer of electrons from one atom to another, creating positively and negatively charged ions attracted to each other.

Cation

Positively charged ion formed when an atom loses electrons.

Anion

Negatively charged ion formed when an atom gains electrons.

Covalent bond

Bond formed by sharing electrons between atoms; can be polar (unequal sharing) or nonpolar (nearly equal sharing).

Polar covalent bond

Covalent bond with unequal sharing of electrons, producing partial charges (δ+ and δ−) on atoms.

Nonpolar covalent bond

Covalent bond with nearly equal sharing of electrons; little to no partial charges.

Hydrogen bond

Intermolecular interaction where a hydrogen atom bonded to an electronegative atom (e.g., O or N) is attracted to another electronegative atom in another molecule; shown as a dotted line.

Bond line representations

Solid line = covalent bond between atoms; dotted line = hydrogen bond between molecules or within a large molecule.

Water polarity

Water’s oxygen is more electronegative, giving partial negative on O and partial positive on H, enabling hydrogen bonding.

Partial charge (δ+ and δ−)

Indication of a slight (not full) positive or negative charge on atoms in polar covalent bonds.

Cohesion

Attraction between like molecules (e.g., water–water) due to hydrogen bonding.

Adhesion

Attraction between water and other polar substances or surfaces (e.g., capillary action on paper towels).

Surface tension

Cohesive forces at the surface of a liquid that create a 'skin,' influenced by hydrogen bonding in water.

Emergent properties

New, complex properties that arise from interactions among components (e.g., water’s properties from hydrogen bonding).

Structure and function

Concept that a molecule’s shape and arrangement determine its biological role; foundational for predicting behavior.

Methane (CH4)

Central carbon bonded to four hydrogens in a tetrahedral arrangement; four sigma bonds.

Tetrahedral geometry

Three-dimensional arrangement around a central atom with four substituents; common in molecules with four electron pairs.

Bond angle (approx. 104.5°)

Angle between bonds around an atom with four electron pairs as discussed in the notes; used to illustrate three‑dimensional shape.

Combustion reaction

Chemical reaction with oxygen producing carbon dioxide (CO2) and water (H2O); e.g., methane combustion.

Aerobic cellular respiration

Biological 'combustion' process where glucose and oxygen yield CO2 and H2O with energy release.

Photosynthesis

Process by which organisms convert light energy, CO2, and water into glucose and oxygen.

Carbon dioxide (CO2)

Gas produced in respiration and combustion; used in photosynthesis as a reactant/product depending on direction of reaction.

Water (H2O)

Polar molecule essential for life; participates in hydrogen bonding and many biochemical processes.

Glucose

A simple sugar produced by photosynthesis and used as fuel in respiration (commonly referenced as a product of photosynthesis and substrate for respiration).

Conservation of matter

Matter is neither created nor destroyed in chemical reactions; atoms are rearranged to form products.

Delta (δ) notation

Symbolic notation for partial charges in polar bonds (δ+ partial positive, δ− partial negative).