M1: Fundamentals of Inorganic Chemistry

Vocabulary flashcards covering key terms, people, models, and quantum concepts from the lecture notes on atomic theory and quantum mechanics.

Atomism

The ancient idea that all matter is composed of indivisible units called atoms; proposed by Leucippus and Democritus; 'atomos' means uncuttable, often imagined as solid spheres.

Leucippus and Democritus

Early thinkers who proposed atomism, describing matter as made of indivisible, solid atoms.

Aristotle

Greek philosopher who argued matter is continuous and proposed the four elements (earth, water, air, fire); opposed Democritus’ atomism.

Dalton’s Atomic Theory / Solid Sphere Model

John Dalton’s 1803 idea that atoms are solid, indivisible spheres (billiard-ball model) forming the basis of the atomic theory.

Electron

Negatively charged subatomic particle discovered via cathode-ray experiments; essential component of atoms.

Cathode-ray tube (CRT)

Experimental setup used to study electric discharges; led to the discovery of the electron and its properties.

J. J. Thomson

Physicist who discovered the electron in 1897 and proposed the Plum Pudding Model of the atom.

Plum Pudding Model

Atomic model in which a diffuse positive charge (pudding) contains embedded negative electrons.

Canal rays

Stream of positive charge observed in cathode-ray experiments; led by Eugen Goldstein.

Eugen Goldstein

Physicist who discovered canal rays, identifying positively charged particles in CRTs.

Nagaoka’s Saturnian model

Early 1900s model proposing a Saturn-like arrangement with a central positive nucleus and surrounding electrons.

Millikan

Physicist who conducted the oil-drop experiment (1909) to measure the electron’s charge.

Rutherford

Physicist who performed the gold foil experiment (1911) leading to the nuclear model of the atom.

Nucleus

The dense, positively charged center of the atom containing protons (and neutrons).

Moseley

Physicist who established the concept of atomic number Z, linking it to the number of protons (and, in neutral atoms, electrons).

Chadwick

Physicist who discovered the neutron (1932) in the nucleus.

Bohr model (Bohr’s Planetary Model)

Atomic model where electrons occupy quantized circular orbits; energy is absorbed or emitted when transitioning between levels.

de Broglie

Physicist who proposed wave-particle duality; electrons exhibit wave-like nature in orbit.

Schrödinger

Physicist who formulated the Electron Cloud Model (Quantum Mechanical Model) describing orbitals as probability regions.

Heisenberg

Physicist who proposed the Uncertainty Principle: position and momentum cannot be precisely known simultaneously.

Quantum Numbers

Four numbers (n, ℓ, mℓ, ms) that describe the energy, shape, orientation, and spin of electron orbitals.

Principal Quantum Number (n)

n indicates the energy level or shell; n = 1, 2, 3, …; higher n means higher energy.

Azimuthal/Orbital Angular Momentum Quantum Number (ℓ)

ℓ describes subshell shape; ℓ = 0 (s), 1 (p), 2 (d), 3 (f); allowed values are 0 to n−1.

Magnetic Quantum Number (mℓ)

Describes orbital orientation in space; for a given ℓ, mℓ ranges from −ℓ to +ℓ.

Spin Quantum Number (ms)

Represents electron spin; values are +1/2 or −1/2; each orbital can hold two electrons with opposite spins.

Hund’s Rule

Within a sublevel, electrons occupy separate degenerate orbitals with parallel spins before pairing occurs.

Aufbau Principle

Electrons fill orbitals from the lowest to the highest energy levels in sequence.

Electron Configuration

Distribution of electrons among atomic orbitals following the Aufbau principle to reach the ground state.

Ground State

The lowest-energy arrangement of electrons in an atom.

s-subshell

ℓ = 0; mℓ = 0; 1 orbital; holds up to 2 electrons; spherical shape.

p-subshell

ℓ = 1; mℓ = −1, 0, +1; 3 orbitals; holds up to 6 electrons; dumbbell shape.

d-subshell

ℓ = 2; mℓ = −2, −1, 0, +1, +2; 5 orbitals; holds up to 10 electrons; clover-like shape.

f-subshell

ℓ = 3; mℓ = −3, −2, −1, 0, +1, +2, +3; 7 orbitals; holds up to 14 electrons; complex shapes.

Valence electrons

Electrons in the outermost shell that determine chemical properties and bonding.

Atomic Number (Z)

Number of protons in the nucleus; in neutral atoms, also equals the number of electrons.

Proton

Positively charged subatomic particle in the nucleus; charge +1.

Neutron

Electrically neutral subatomic particle in the nucleus; contributes to atomic mass.