BC 212 Lecture 1: Building Blocks of Molecules

Vocabulary practice flashcards covering basic chemical definitions, atomic structure, periodic properties, octet rule, bonding types, and essential polyatomic ions from BC 212 Lecture 1.

Matter

Physical material of the universe; anything that has mass and occupies space.

Mass

The amount of matter present in an object.

Pure Substance

Matter that has a uniform chemical composition throughout.

Mixture

Matter with a variable composition that can be physically separated into pure substances.

Molecule

The smallest unit of a pure substance that retains its chemical properties, made up of two or more atoms.

Atom

The smallest particle of matter that defines a chemical element.

Element

A homogeneous, pure substance consisting of only one kind of atom.

Compound

A homogeneous, pure substance composed of multiple kinds of atoms combined in fixed proportions.

Neutral Atom

An uncharged element containing equal numbers of protons and electrons.

Atomic Number ($Z$)

The total number of protons in the nucleus of an element.

Mass Number ($A$)

The total number of protons plus neutrons in an atom.

Isotopes

Atoms of the same element that have the same number of protons (atomic number) but different numbers of neutrons.

Atomic Weight

The average mass of an element based on the relative abundance of its naturally occurring isotopes.

Molecular Weight

The sum of the atomic weights for all of the individual atoms in a molecule.

Protium ($^1_1\text{H}$)

The hydrogen isotope containing $1$ proton and $0$ neutrons, with a mass number of $1$.

Deuterium ($^2_1\text{H}$)

The hydrogen isotope containing $1$ proton and $1$ neutron, with a mass number of $2$.

Tritium ($^3_1\text{H}$)

The hydrogen isotope containing $1$ proton and $2$ neutrons, with a mass number of $3$.

Period

A horizontal row in the periodic table, representing the principal quantum number ($n$) or valence shell energy level.

Group (Family)

A vertical column in the periodic table containing elements with similar subshells and chemical properties.

Valence Shell

The outermost electron shell of an atom, associated with its highest energy level.

Valence Electron

An electron located in the valence shell of an atom that participates in chemical bonding.

Metallic Character

The set of physical properties including heat and electricity conductivity, malleability into sheets, ductility into wires, and luster, which increases down and to the left on the periodic table.

Ionization Energy

The amount of energy required to remove an electron from a gaseous atom or ion ($\text{El} \rightarrow \text{El}^+ + e^-$).

Electronegativity

A measure of how tightly an atom holds onto electrons in a bond, increasing toward the top-right of the periodic table.

Reactivity

A measure of how easily an element loses or gains electrons during a chemical reaction.

Noble Gases

Group VIIIA (18) elements characterized as colorless, inert, and highly stable due to having a completely filled valence shell ($s^2p^6$).

Octet Rule

The principle that atoms gain, lose, or share electrons in order to achieve a stable full valence shell of $8$ electrons.

Lewis Symbol

A visual representation of an atom that uses dots surrounding the element symbol to depict its valence electrons.

Ionic Bonding

A type of chemical bonding resulting from the transfer of electrons between atoms, creating oppositely charged ions held together by electrostatic attraction.

Covalent Bonding

A type of chemical bonding in which two atoms share one or more pairs of valence electrons to achieve filled octets.

Cation

A positively charged ion formed when an atom loses electrons through oxidation, resulting in more protons than electrons.

Anion

A negatively charged ion formed when an atom gains electrons through reduction, resulting in more electrons than protons.

Polyatomic Ion

An ion composed of two or more covalently bonded atoms carrying an overall net electrical charge.

Ammonium

A polyatomic cation with the chemical formula $\text{NH}_4^+$.

Hydronium

A polyatomic cation with the chemical formula $\text{H}_3\text{O}^+$.

Hydroxide

A polyatomic anion with the chemical formula $\text{OH}^-$.

Bicarbonate

A polyatomic anion with the chemical formula $\text{HCO}_3^-$.

Carbonate

A polyatomic anion with the chemical formula $\text{CO}_3^{2-}$.

Sulfate

A polyatomic anion with the chemical formula $\text{SO}_4^{2-}$.

Phosphate

A polyatomic anion with the chemical formula $\text{PO}_4^{3-}$.

Cyanide

A polyatomic anion with the chemical formula $\text{CN}^-$.