Topic 1.1: Structural Water and Hydrogen Bonding

Vocabulary flashcards covering water's structure, polarity, hydrogen bonding, cohesion, adhesion, surface tension, emergent properties, solubility, ice density, and heat capacity.

Water (H2O)

A molecule composed of two hydrogen atoms covalently bonded to one oxygen atom; polar due to unequal sharing of electrons.

Covalent bond

A chemical bond formed when atoms share electrons.

Polar covalent bond

A covalent bond in which electrons are shared unequally, creating partial charges due to differing electronegativities.

Polarity

Unequal distribution of electric charge within a molecule, producing partial positive and negative regions.

Hydrogen bond

A weak interaction between a hydrogen atom bonded to an electronegative atom and another electronegative atom; enables hydrogen bonding between water molecules and other polar molecules.

Cohesion

Attraction between like molecules (e.g., water–water) driven by hydrogen bonding.

Adhesion

Attraction between unlike molecules (e.g., water–amino acid) due to hydrogen bonding.

Surface tension

A property arising from stronger hydrogen bonding at the surface of water, causing the surface to act like a stretched skin.

Emergent properties

Properties that arise from interactions among water's components, such as cohesion, adhesion, and surface tension.

Solubility (solvency) of water

Water's ability to dissolve many substances in its liquid state; not a universal solvent, but highly effective for many nutrients and salts.

Universal solvent caveat

Water is not a universal solvent; its solvent capabilities vary with the substance.

Ice floats (density anomaly)

Ice is less dense than liquid water due to hydrogen-bonded lattice, causing ice to float on water.

High heat capacity of water

Water's ability to absorb or store large amounts of thermal energy with only modest changes in temperature.