The Chemistry of Life: Water and Chemical Bonding

Vocabulary-based flashcards covering the fundamentals of atomic bonding, polar vs. nonpolar covalent bonds, and the unique properties of water based on the chemistry of life lecture.

Rule #1 For Bonding

Opposite charges attract each other, while like charges repel each other.

Electrons

Negatively charged subatomic particles that are attracted to protons in other atoms.

Protons

Positively charged subatomic particles found in the nucleus of an atom.

Chemical Bonds

The forces that hold atoms together in compounds; the main types are ionic and covalent.

Covalent Bond

A bond that forms when electrons are shared between atoms.

Compound

The structure that results when atoms are joined together specifically by covalent bonds.

Molecule

The smallest unit of a compound.

Polar Covalent Bond

A bond formed when the shared pair of electrons in a covalent bond are not shared equally between atoms, resulting in partial charges.

Non-Polar Covalent Bond

A bond where electrons are shared equally between atoms, meaning no partial charges are formed.

$\delta-$ (Partial negative charge)

The characteristic an element takes on when it pulls shared electrons closer to itself in a polar covalent bond.

$\delta+$ (Partial positive charge)

The characteristic an element takes on when its shared electrons are pulled away from it for an unequal amount of time in a polar covalent bond.

Non-Polar Molecules

Substances like oils, fats, and waxes that share electrons equally, do not have partial charges, and do not interact with water.

Like Likes Like

A chemist's saying indicating that polar molecules attract other polar molecules due to partial charges, and nonpolar molecules attract other nonpolar molecules.

Hydrogen Bond

An attraction between opposite partial charges on different molecules, typically occurring when hydrogen is bonded to nitrogen, oxygen, or fluorine.

High Specific Heat

A property of water where it resists temperature changes because significant energy is required to break the hydrogen bonds between molecules.

Cohesion

The attraction between water molecules and other water molecules.

Adhesion

The attraction between water molecules and other polar molecules, such as those found in cotton clothes.

Surface Tension

The property resulting from water molecules at the surface forming stronger bonds with each other.

Expansion on Freezing

A process where hydrogen bonds push $H_2O$ molecules farther apart into a stable hexagonal crystal lattice structure, increasing intermolecular space and volume.

Hydration Shells

The arrangement of water molecules around dissolved ions, such as the surrounding of $Na^+$ and $Cl^-$ in a salt solution.

Capillary Action

A phenomenon that occurs when adhesion is greater than cohesion, allowing water to "climb" through small diameter tubes or xylem cells.

Meniscus

The curved upper surface of a liquid, like water, in a tube.