AP Chemistry - Unit 2

Flashcards covering the history of the atom, its parts, isotopes, chemical formulas, and nomenclature.

Leucippus and Democritus

Greek philosophers who proposed that matter could be divided until reaching an indivisible particle called "atomos."

John Dalton

Proposed that matter is composed of tiny, indestructible spheres called atoms and that elements combine in specific mass ratios.

J.J. Thomson

Discovered the electron and proposed the "plum pudding" model of the atom.

Ernest Rutherford

Conducted the gold foil experiment and proposed that the atom has a tiny, positive nucleus with electrons surrounding it.

Niels Bohr

Discovered that electrons are quantized and move around the nucleus in fixed orbits with specific energy values.

Erwin Schrödinger

Proposed that electrons exist as matter waves and are described by mathematical equations that create orbitals, areas of high probability density.

Nucleus

The central part of an atom containing protons and neutrons.

Orbitals

Regions surrounding the nucleus where electrons are most likely to be found.

Atomic Number (Z)

The number of protons in the nucleus of an atom.

Mass Number (A)

The sum of protons and neutrons in the nucleus of an atom.

Isotopes

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

Isotope Notation

Shows the symbol of the element, its mass number, and its atomic number.

Atomic Mass

The average of mass number values of naturally occurring isotopes for a sample of an element weighted by each isotope’s percent natural abundance.

Mass Spectrometry

A method of separating isotopes according to mass and creating a graph.

Monatomic Ion

A single atom that has gained or lost electrons, resulting in a positive or negative charge.

Ionic Compounds

Substances made of charged particles held together in a crystalline pattern by electrostatic attraction.

Molecular Compounds

Compounds made of nonmetal elements bound together by shared electrons (a covalent bond).

Polyatomic Ion

A group of covalently bonded atoms with a net positive or negative charge.

Molecular Formula

Shows how many atoms of each type are found in a molecule.

Empirical Formula

Shows the ratio of each type of atom in a compound in lowest terms.

IUPAC Nomenclature

The systematic naming system used to name chemicals.

Cations

Ions formed from metal atoms that have the same name as the metal, followed by the word "ion".

Anions

Monatomic ions that replace their ending with "-ide".

Oxyanions

Anions containing oxygen.

Naming Acids (-ide)

Acids derived from anions ending in "-ide" start with "hydro-" and end with "-ic acid".

Naming Acids (-ate)

Acids derived from anions ending in "-ate" end in "-ic".

Naming Acids (-ite)

Acids derived from anions ending in "-ite" end in "-ous".

Organic Chemistry

The study of carbon-based molecules.

Hydrocarbon

An organic molecule made of only carbon and hydrogen.

Functional Groups

Specific substituents within molecules responsible for their characteristic chemical reactions.