General Chemistry Key Concepts and Vocabulary

Comprehensive vocabulary flashcards covering key topics in general chemistry, including measurements, atomic structure, stoichiometry, chemical reactions, and nomenclature.

Significant Figures

The meaningful numbers in a measurement that are known with certainty plus one estimated final digit of uncertainty.

Insignificant Figures

Meaningless numbers in a measurement that do not contribute to precision or accuracy, such as leading zeroes.

Exact Numbers

Numbers known with complete certainty through counting or defined values, such as $3$ apples.

Captive Zeroes

Zeroes located between two non-zero digits that are always counted as significant figures.

Trailing Zeroes

Zeroes at the end of a number that are significant only if they follow a decimal point in the decimal portion.

Accuracy

A measure of how close a measured value is to the actual or true value.

Precision

A measure of how reproducible or consistent multiple measurements are under identical conditions.

Error

Limiting factors in an experiment or measuring instrument that prevent a measurement from being $100\,\%$ precise or accurate.

Scientific Notation

A method of writing numbers in the form $N \times 10^a$ to condense large values and express precision.

Matter

Anything that possesses mass and occupies space.

Atom

The smallest unit of matter that serves as the basic building block of all elements.

Strong Nuclear Force

The force used by neutrons in the nucleus to overcome proton-proton repulsion and hold the atomic nucleus together.

Neutral Atom

The standard form of an atom where the number of positively charged protons equals the number of negatively charged electrons.

Ion

An atom or group of atoms that has acquired a positive or negative electric charge by gaining or losing electrons.

Element

A group of atoms that all share the exact same number of protons in their nuclei.

Isotope

A variation of an element that has the same number of protons but a different number of neutrons.

Compound

A pure substance formed of two or more different elements chemically bonded together in fixed proportions.

Atomic Mass Number

The total sum of protons and neutrons present within an atom's nucleus.

Relative Atomic Mass

The average mass of all naturally occurring isotopes of an element divided by $\frac{1}{12}$ of the mass of a carbon atom.

Radioactive Decay

The breakdown of an unstable atomic nucleus accompanied by the emission of alpha or beta particles.

Mass Spectrometry

An analytical instrument technique used to identify components of a sample by separating ions based on their mass-to-charge ratios.

Law of Definite Proportions

A chemical principle stating that a given chemical compound always contains its constituent elements in a constant ratio by mass.

Percent Composition

The relative mass of each individual element contained within a compound expressed as a percentage.

Mole

The standard chemical unit equal to $6.02 \times 10^{23}$ representative particles (Avogadro's number).

Molar Mass

The mass of one mole of a substance expressed in units of $\text{g\,mol}^{-1}$.

Dimensional Analysis Table

A tabular format used to convert units by placing an input quantity next to a fractional conversion factor to calculate an output.

Pure Substance

A sample of matter consisting of only one type of element or compound with uniform chemical composition.

Mixture

A combination of two or more pure substances that are physically mixed without being chemically bonded.

Molecular Formula

A formula stating the actual total number of atoms of each element contained in a covalent molecule.

Empirical Formula

A chemical formula showing the simplest reduced whole-number ratio of elements in a compound.

Combustion Analysis

An analytical method where an organic compound is burned in pure oxygen to determine the masses of its constituent elements.

Bohr Model

An atomic model proposed by Ernest Rutherford and Niels Bohr depicting electrons orbiting a central nucleus in fixed circular pathways.

Quantum Mechanical Model

The modern atomic model proposed by Schrodinger that represents electron locations as electron clouds and probability regions.

Electron Configuration

The specific arrangement of electrons across energy levels and atomic orbitals within an atom.

Orbital

A defined region of space around an atomic nucleus where electrons are most likely to be found, categorized as s, p, d, or f.

Ground State

The lowest possible energy state accessible to an atom or molecule.

Excited State

A state achieved when an electron absorbs energy and temporarily jumps to a higher energy level.

Aufbau Principle

A rule stating that electrons must fill lower-energy atomic orbitals completely before filling higher-energy orbitals.

Hund's Rule

A rule stating that every orbital in a subshell must be singly occupied by an electron before any orbital is doubly occupied.

Pauli Exclusion Principle

A principle stating that two electrons residing in the same orbital must possess opposite spins.

Photoelectron Spectroscopy

An experimental technique used to measure the binding energies of electrons in atoms by irradiating them with photons.

Binding Energy

The attractive energy exerted by the nucleus to hold electrons in specific energy shells.

Effective Nuclear Charge

The net positive electrostatic force experienced by valence electrons, given by $Z_{\text{eff}} = Z - S$.

Periodic Table Element Box

A display tile on the periodic table showing an element's atomic number, element symbol, element name, and atomic mass.

Physical Change

A process involving changes in intermolecular interactions without altering the underlying chemical composition of a substance.

Chemical Change

A process that alters the chemical composition of a substance by breaking or forming chemical bonds in a chemical reaction.

Acid-Base Reaction

A chemical reaction involving the transfer of at least one proton ($\text{H}^+$ ion) between chemical species.

General Reaction Types Summary Table

A reference chart outlining the standard general equations for combination, decomposition, single displacement, double displacement, and combustion reactions.

Synthesis Reaction

A chemical reaction where multiple reactants combine to form a single product ($A + B \rightarrow C$).

Decomposition Reaction

A chemical reaction where a single compound breaks down into two or more simpler substances ($AB \rightarrow A + B$).

Single Displacement Reaction

A reaction in which an uncombined element replaces an element within a compound ($A + BC \rightarrow AC + B$).

Double Displacement Reaction

A reaction where two reactant compounds exchange constituent elements to form two new compound products ($AB + CD \rightarrow AD + CB$).

Combustion Reaction

A chemical reaction in which a substance reacts rapidly with oxygen gas, generating oxides like $\text{CO}_2$ and $\text{H}_2\text{O}$.

Redox Reaction

A chemical reaction involving the transfer of electrons between species, encompassing oxidation and reduction.

Oxidation

The loss of electrons by an atom, ion, or compound during a chemical reaction.

Reduction

The gain of electrons by an atom, ion, or compound during a chemical reaction.

Law of Conservation of Mass

A fundamental principle stating that mass cannot be created or destroyed in a closed system during a reaction.

Limiting Reactant

The reactant in a chemical reaction that is completely consumed first, limiting the maximum product formation.

Excess Reactant

The reactant that remains unreacted after the limiting reactant is completely consumed in a chemical process.

Theoretical Yield

The maximum mass of product that can form based on stoichiometric calculations assuming complete consumption of the limiting reactant.

Actual Yield

The mass of product that is actually recovered from a chemical reaction performed experimentally.

Percent Yield

The ratio evaluating reaction efficiency, calculated as $\frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100\,\%$.

Chemical Nomenclature

A standardized set of rules used by chemists to generate systematic and unambiguous names for chemical compounds.

Covalent Compounds

Compounds formed when nonmetal atoms share electrons to construct covalent chemical bonds.

Ionic Compounds

Compounds formed by electrostatic attraction between positively charged cations and negatively charged anions.

Pauling Scale

A scale based on electronegativity differences used to classify chemical bonds as non-polar covalent, polar covalent, or ionic.

Covalent Prefix Rules Table

A chart defining the numerical prefixes (mono-, di-, tri-, tetra-, penta-, hexa-) applied in covalent compound naming.

Oxyanion

A polyatomic anion containing one central atom covalently bonded to one or more oxygen atoms.

Oxyanion Naming Scheme Table

A systematic grid mapping oxygen atom counts to specific prefixes (-hypo, -per) and suffixes (-ite, -ate) for oxyanions.

Chlorine Oxyanion Series Table

An exemplary table listing the four oxygen-containing polyatomic anions of chlorine: hypochlorite, chlorite, chlorate, and perchlorate.

Oxyacid

An acidic compound composed of hydrogen combined with an oxygen-containing polyatomic ion (oxyanion).