Foundations of General Chemistry – Chapters 1-4

These vocabulary flashcards review essential terms and definitions from Chapters 1-4, covering matter, measurements, atomic structure, the periodic table, and ionic bonding.

Matter

Anything that has mass and occupies space.

Chemistry

The study of the characteristics, composition, and transformations of matter.

Solid

State of matter with definite shape and definite volume.

Liquid

State of matter with indefinite shape but definite volume; takes the shape of its container.

Gas

State of matter with indefinite shape and indefinite volume; completely fills its container.

Physical Property

Characteristic that can be observed without changing a substance’s chemical identity (e.g., color, melting point).

Chemical Property

Characteristic that describes how a substance undergoes or resists change to form a new substance (e.g., iron rusting).

Physical Change

A change in physical appearance without altering chemical composition (e.g., melting ice).

Chemical Change

A process that alters the chemical composition, producing new substances (e.g., burning wood).

Pure Substance

Matter that cannot be separated into other kinds of matter by physical means; includes elements and compounds.

Mixture

Physical combination of two or more pure substances that retain their own identities.

Element

Pure substance that cannot be broken down into simpler substances by chemical means.

Compound

Pure substance that can be broken down into two or more elements by chemical means.

Homogeneous Mixture

Mixture with only one visible phase and uniform properties throughout.

Heterogeneous Mixture

Mixture containing visibly different phases with differing properties.

Atom

Smallest particle of an element that retains the properties of that element.

Molecule

Group of two or more atoms held together that behaves as a single unit.

Homoatomic Molecule

Molecule whose atoms are all of the same element (e.g., O₂).

Heteroatomic Molecule

Molecule containing two or more different elements (e.g., CO₂).

Chemical Formula

Notation using element symbols and numerical subscripts to show the composition of a compound.

Density

Mass per unit volume of a substance (g/cm³, g/mL, or g/L).

Significant Figures

All certain digits in a measurement plus the first uncertain (estimated) digit.

Scientific Notation

Expression of numbers in the form A × 10ⁿ with one non-zero digit to the left of the decimal.

Conversion Factor

Ratio that expresses how one unit of measurement equals another, used for unit conversions.

Dimensional Analysis

Problem-solving method that uses conversion factors to keep track of units while converting quantities.

Subatomic Particle

Building block of atoms; includes protons, neutrons, and electrons.

Proton

Positively charged subatomic particle found in the nucleus.

Neutron

Neutral subatomic particle located in the nucleus.

Electron

Negatively charged subatomic particle that occupies regions outside the nucleus.

Atomic Number (Z)

Number of protons in the nucleus of an atom.

Mass Number (A)

Sum of protons and neutrons in an atom’s nucleus.

Isotope

Atoms of the same element with the same number of protons but different numbers of neutrons.

Atomic Mass

Weighted average mass of an element’s naturally occurring isotopes expressed in atomic mass units (amu).

Periodic Law

When elements are arranged by increasing atomic number, similar chemical properties recur at periodic intervals.

Period

Horizontal row in the periodic table.

Group (Family)

Vertical column in the periodic table; elements share similar valence-electron configurations.

Metal

Element characterized by luster, electrical and thermal conductivity, and malleability.

Nonmetal

Element lacking metallic properties; often brittle, non-conductive, and may be solid, liquid, or gas.

Electron Shell

Region around the nucleus containing electrons with similar energy and distance from the nucleus.

Subshell

Subdivision of an electron shell designated s, p, d, or f, each with a specific capacity for electrons.

Orbital

Region within a subshell where an electron with a given energy is most likely found; holds max two electrons.

Electron Configuration

Statement of how many electrons occupy each subshell of an atom.

Valence Electron

Electron in the outermost shell of an atom that can participate in bonding.

Lewis Symbol

Element symbol surrounded by dots representing the atom’s valence electrons.

Octet Rule

Atoms tend to gain, lose, or share electrons to achieve eight valence electrons, like a noble gas.

Ion

Atom or group of atoms with a net electrical charge due to loss or gain of electrons.

Cation

Positively charged ion formed by electron loss.

Anion

Negatively charged ion formed by electron gain.

Isoelectronic Species

Atoms or ions having the same electron configuration and number of electrons.

Ionic Bond

Electrostatic attraction between oppositely charged ions formed by electron transfer.

Covalent Bond

Bond formed by sharing one or more pairs of electrons between atoms.

Formula Unit

Smallest whole-number ratio of ions that results in electrical neutrality in an ionic compound.

Polyatomic Ion

Charged species composed of two or more covalently bonded atoms acting as a single ion (e.g., SO₄²⁻).