Matter and Its Properties - Vocabulary Flashcards (General Chemistry 1)

A set of vocabulary flashcards covering core terms from matter, properties, mixtures, separation techniques, and atomic theory as presented in the lecture notes.

Anything that has mass and occupies space.

Matter

Substance

A form of matter with a definite composition (elements or compounds).

State of Matter

The physical form of matter: solid, liquid, or gas.

Physical Property

A characteristic observed without changing the substance’s composition.

Chemical Property

A characteristic that describes how a substance alters its composition during a chemical change.

Intensive Property

Property that does not depend on the amount of matter (e.g., boiling point, density, color).

Extensive Property

Property that depends on the amount of matter (e.g., mass, volume).

Pure Substances

Substances with fixed composition (elements or compounds).

Element

Substance consisting of one type of atom; cannot be chemically broken down.

Compound

Substance with two or more elements chemically bonded; can be decomposed chemically.

Mixture

Two or more substances physically combined with variable composition.

Homogeneous Mixture

Uniform composition; also called a solution.

Heterogeneous Mixture

Non-uniform composition; components are not evenly distributed.

Solvent

The component in the greatest amount that dissolves a solute.

Solute

The substance dissolved in the solvent.

Filtration

Separation of an insoluble solid from a liquid using a filter.

Filtrate

Liquid that passes through the filter in filtration.

Residue

Material left on the filter after filtration.

Evaporation

Separating a dissolved solid from a liquid by boiling away the solvent.

Distillation

Separation of liquids by boiling points and condensation of vapors.

Decanting

Pouring off a liquid to separate a denser layer or sediment.

Chromatography

Separation based on how substances interact with a stationary phase vs. a mobile phase.

Tyndall Effect

Scattering of light by colloidal particles, indicating a colloid, not a solution.

Solubility

The ability of a substance to dissolve in a particular solvent.

Density

Mass per unit volume; an intensive property used to distinguish substances.

Boiling Point

Temperature at which a liquid boils.

Phase Change

Transition between solid, liquid, and gas; isothermal (constant temperature) process.

Dalton’s Atomic Theory

Postulates about atoms: matter is made of atoms; atoms of the same element are identical; compounds form by combining atoms in fixed ratios; in reactions, atoms are rearranged, not created or destroyed.

Law of Conservation of Mass

Total mass of reactants equals total mass of products.

Law of Definite Proportions (Constant Composition)

A compound contains the same elements in the same proportion by mass.

Law of Multiple Proportions

Fixed masses of elements combine in small whole-number ratios to form compounds.

Atomic Number

Number of protons in the nucleus; defines the identity of an element.

Mass Number

Sum of protons and neutrons in the nucleus.

Isotope

Atoms of the same element with different numbers of neutrons (different mass).

Ion

Atom or group with a net electric charge.

Cation

Positively charged ion (fewer electrons than protons).

Anion

Negatively charged ion (more electrons than protons).

Isoelectronic

Atoms/ions/molecules that have the same number of electrons.

Electron Configuration

Arrangement of electrons in an atom’s orbitals.

Aufbau Principle

Electrons occupy the lowest-energy orbitals first in order of increasing energy.

Pauli Exclusion Principle

No two electrons in an atom can have the same set of quantum numbers; orbitals hold at most two electrons with opposite spins.

Hund’s Rule

Electrons occupy separate orbitals of a subshell before pairing.

Orbital

Region around an atom’s nucleus where there is a high probability of finding an electron.

Paramagnetic

Atoms with unpaired electrons that are attracted to a magnetic field.

Diamagnetic

Atoms with all electrons paired; slightly repelled by a magnetic field.

Diatomic Molecules

Molecules composed of two atoms (e.g., H2, N2, O2, F2, Cl2, Br2, I2).