Chapter 2: Atomic Theory & Chemical Nomenclature Practice Flashcards

Vocabulary-style flashcards covering pre-atomic theory, major experiments in atomic history, atomic structure definitions, periodic table groups, types of chemical bonding, and nomenclature rules for ionic, molecular, and organic compounds.

Law of Conservation of Mass

A principle stated by Antoine Lavoisier in 1789 that if all reactants and products are collected before and after a reaction, the total mass of a reaction stays the same.

Law of Definite Proportions

Stated by Joseph Proust in 1794, it posits that when elements combine into compounds, they always occur in set ratios regardless of the amount of the compound.

Brownian Motion

The small random motion of solution particles, identified by Robert Brown in 1827 and mathematically explained by Einstein in 1905 as the result of microscopic collisions of atoms.

Dalton’s Atomic Theory

A theory from 1808 stating elements are composed of atoms, atoms of a given element are identical, and chemical reactions involve only the separation, combination, or rearrangement of atoms.

J.J. Thomson

Scientist who used the Cathode Ray Tube in 1897 to discover electron particles and measured the charge/mass ratio of the electron as $-1.76 \times 10^{8}\,C/g$.

Plum-pudding model

Thomson’s 1904 atomic model depicting the atom as electrons scattered throughout a spherical cloud of evenly distributed positive charge.

Millikan’s Oil Drop Experiment

A 1910 experiment that measured the charge of the electron as $-1.60 \times 10^{-19}\,C$ and determined its mass as $9.10 \times 10^{-28}\,g$.

Rutherford’s Gold Foil Experiment

An experiment performed in 1910-11 that demonstrated the positive charge of an atom is concentrated in a tiny nucleus rather than distributed as a cloud.

Neutron

A neutral subatomic particle discovered by James Chadwick in 1932 with a mass approximately equal to that of a proton ($1.67 \times 10^{-24}\,g$).

Atomic number (Z)

A whole number that represents the number of protons in an atom and uniquely identifies each element.

Mass number (A)

The total number of nucleons, which includes both protons and neutrons, in an atom.

Isotopes

Atoms of the same element that have an equal number of protons but a varying number of neutrons, resulting in different mass numbers.

Cation

An ion with a positive charge resulting from the loss of electrons, typically during oxidation.

Anion

An ion with a negative charge resulting from the gain of electrons, typically during reduction.

Alkali Metals

The elements in Group 1A of the periodic table, excluding Hydrogen.

Chalcogens

The elements in Group 16 of the periodic table.

Diatomic molecules

Seven elements that naturally occur as two-atom molecules: $H_{2}$, $N_{2}$, $O_{2}$, $F_{2}$, $Cl_{2}$, $Br_{2}$, and $I_{2}$.

Crystal Lattice

The 3D structure of alternating cations and anions that forms an ionic compound rather than a discrete molecule.

Formula unit

The simplest ratio of ions in an ionic compound, such as $NaCl$ or $CaF_{2}$.

Polyatomic ions

Molecules that carry a net charge and participate in ionic compounds while acting as single units.

Ionic Bond

A chemical bond occurring between metals and non-metals where electrons are exchanged and held together by electrostatic attraction.

Covalent Bond

A chemical bond between non-metal atoms where electrons are shared between them.

Hydrates

Ionic compounds that have a specific number of water molecules attached to their crystal lattice, such as $CuSO_{4} \cdot 5H_{2}O$.

Oxoacid

An acid that contains hydrogen, oxygen, and another central element, such as Nitric acid ($HNO_{3}$).

Base

A substance that yields hydroxide ions ($OH^{-}$) when dissolved in water, acting as an anti-acid to neutralize acids.

Hydrocarbons

Organic molecules containing only carbon and hydrogen, classified as alkanes, alkenes, or alkynes based on their bonding.

Functional Groups

Specific arrangements of atoms, such as Alcohols ($-OH$) or Carboxylic Acids ($-COOH$), that give organic substances similar chemical properties.