LO2 - Inorganic Chemical Components of Living Organisms

Vocabulary practice flashcards covering inorganic chemistry concepts, subatomic particles, chemical bonding, water properties, redox reactions, and pH buffers.

Element

A pure chemical substance consisting of only one type of atom.

Essential Elements

Chemical elements responsible for $>96\%$ of the mass of living organisms, with carbon, hydrogen, oxygen, and nitrogen making up approximately $99\%$.

Trace Elements

Chemical elements critical for life that are found in small amounts in living organisms, such as iodine, manganese, copper, zinc, and iron.

Atom

The smallest unit of an element that retains the chemical properties of its element type, composed of subatomic particles such as protons, neutrons, and electrons.

Atomic Number

The specific number of protons an atom has, which identifies its element type.

Atomic Mass

The mass of all subatomic particles in an atom, calculated by adding the number of protons and neutrons (each having a mass of $1\,amu$ or dalton).

Isotope

Atoms of the same element that have the same atomic number but differ in neutron number and atomic mass.

Radioisotope

An unstable isotope that decays over time into a more stable isotope, such as $^{14}C$ decaying to $^{14}N$.

Valence Shell

The outermost ring of an atom in a Bohr model, containing electrons that possess the most energy.

Valence Electrons

Electrons located in the outermost valence shell of an atom that mostly determine its chemical behavior and reactivity.

Covalent Bond

A strong, stable chemical bond formed when atoms share valence electrons to fill their valence shells.

Electronegativity

An element's affinity or attraction for electrons in a chemical bond.

Nonpolar Covalent Bond

A covalent bond formed between atoms with similar electronegativities, resulting in equal sharing of electrons.

Polar Covalent Bond

A covalent bond formed between atoms with different electronegativities, resulting in unequal electron sharing and partial positive and negative charges.

Ion

An atom or molecule that has acquired an electrical charge by gaining or losing one or more electrons.

Cation

A positively charged ion formed when an atom loses one or more electrons, leaving it with more protons than electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons, leaving it with more electrons than protons.

Ionic Bond

A chemical bond formed between oppositely charged cations and anions due to electron transfer, which tends to dissociate in water.

Hydrogen Bond

A weak attraction between a hydrogen atom with a partial positive charge (in a polar covalent bond) and an electronegative atom (usually oxygen or nitrogen) with a partial negative charge.

van der Waals Interactions

Weak, short-range attractions between nonpolar molecules occurring in regions of temporary slight opposite charges caused by random electron movement.

Oxidation

A chemical reaction in which an atom, ion, or molecule loses one or more electrons (and energy).

Reduction

A chemical reaction in which an atom, ion, or molecule gains one or more electrons (and energy).

Cohesion

The property of water molecules forming hydrogen bonds with one another.

Adhesion

The property of water molecules forming hydrogen bonds with other substances.

Hydrophilic

Substances that readily interact with or dissolve in water, including most polar and ionic compounds.

Hydrophobic

Nonpolar substances that are insoluble in water and tend to cluster together to avoid surrounding water molecules.

Specific Heat

The amount of heat energy required to change the temperature of a substance; water's high specific heat requires breaking hydrogen bonds before increasing molecular kinetic energy.

Heat of Vaporization

The amount of heat energy required to convert a liquid into a gas; water's high heat of vaporization enables evaporative cooling.

Acid

A proton donor that dissociates in aqueous solution to yield hydrogen ions ($H^+$).

Base

A proton acceptor that dissociates in aqueous solution to yield hydroxide ions ($OH^-$).

pH

A measurement indicating the hydrogen ion concentration ($mol/L$) of a solution, where values below $7$ are acidic and above $7$ are basic.

Buffer System

A combination of a weak acid and a weak base that resists drastic changes in $pH$ by accepting or donating hydrogen ions.