Properties of Water and Carbon Chemistry

Vocabulary flashcards covering the physical and chemical properties of water, solution behaviors, thermal properties, and the chemical foundation of carbon based on lecture notes.

Polar Molecule

A molecule that has one negatively charged end and one positively charged end due to unequal sharing of electrons, such as a water molecule with a partially negative ($\delta^-$) oxygen atom and partially positive ($\delta^+$) hydrogen atoms.

Intramolecular Bonds

Strong chemical bonds, such as polar covalent bonds, that hold atoms together within the same molecule.

Intermolecular Bonds

Bonds or interactions between different molecules, such as the weak hydrogen bonds between neighboring water molecules that constantly break and reform.

Cohesion

The attraction between water molecules due to hydrogen bonding, which creates surface tension and creates continuous water columns pulled upward in plant xylem during transpiration.

Adhesion

The attraction between water and other polar or charged substances, allowing water to cling to cellulose in plant cell walls and refill air-filled xylem vessels.

Capillary Action

The movement of water up narrow vertical spaces when water enters capillary tubes, adheres to the tube walls, and pulls other water molecules upward through cohesion.

Hydrophilic

Water-loving substances consisting of polar molecules (e.g., glucose) or charged ions (e.g., $NaCl$) that readily dissolve in or form hydrogen bonds with water.

Hydrophobic

Water-fearing substances consisting of non-polar molecules (e.g., lipids, oils, fats) that do not form hydrogen bonds with water and are attracted more to each other.

Buoyancy

The upward force exerted by a fluid on an object, equal to the weight of the displaced water, allowing organisms to float if their density is lighter than the fluid.

Viscosity

The resistance of a fluid to flow due to internal friction, where hydrogen bonds in water create friction (making air viscosity $50\times$ lower than water viscosity).

Thermal Conductivity

A measure of how easily a substance transfers heat through itself, where water has high thermal conductivity compared to fats/oils (which conduct $\approx 25\%$ as fast) and air (which conducts $\approx 5\%$ as fast).

Specific Heat Capacity

The amount of energy required to raise the temperature of $1\,kg$ of a substance by $1\,^\circ C$ (water has a high value of $4200\,J/kg/^\circ C$, keeping aquatic habitats thermally stable).

Evaporative Sweat Cooling

A body temperature regulation mechanism where heat energy breaks cohesive hydrogen bonds between water molecules, allowing evaporation to absorb and remove body heat.

Chemical Properties of Carbon

The fundamental features of carbon that allow it to form 4 covalent bonds to build simple, chain, or branched structures essential for forming stable yet reactive biomolecules.

Early Earth Water Retention Factors

The physical factors that retained liquid water and water vapor on early Earth, specifically Earth's ideal distance from the Sun (temperature balance) and Earth's gravity (preventing gas escape).