Structure and Properties of Matter

A collection of vocabulary flashcards based on key concepts related to the structure and properties of matter from the lecture.

Atom

The smallest unit of an element, made up of sub-atomic particles: protons, neutrons, and electrons.

Democritus

An ancient philosopher who proposed the particulate nature of matter and coined the term 'atoms' around 500 BC.

John Dalton

A scientist who formulated the first scientific theory on the atom and proposed that atoms are indivisible.

Atomic Theory

The theory that matter is composed of discrete units called atoms.

Elements

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

Isotopes

Atoms of the same element that have different masses due to varying numbers of neutrons.

Quantum Number

A number that describes the quantized state of an electron in an atom; includes principal, azimuthal, magnetic, and spin quantum numbers.

Schrödinger Equation

A mathematical equation that describes the behavior of electrons in an atom.

Uncertainty Principle

A principle introduced by Werner Heisenberg indicating that it's impossible to know both the position and momentum of an electron simultaneously.

Orbital

A region in space around a nucleus where there is a high probability of finding an electron.

Aufbau Principle

The principle that electrons fill atomic orbitals starting with the lowest energy levels before higher ones.

Pauli Exclusion Principle

A principle stating that no two electrons in an atom can have the same set of four quantum numbers.

Hund's Rule

The rule that states that electrons will occupy degenerate orbitals singly before pairing in the same orbital.

Wave-Particle Duality

The concept that electrons exhibit both wave-like and particle-like properties.

Subshell

A subdivision of electron shells that contain one or more orbitals, identified by quantum numbers.

Proton

A positively charged sub-atomic particle found in the nucleus of an atom.

Neutron

A neutral sub-atomic particle found in the nucleus of an atom.

Electron

A negatively charged sub-atomic particle that orbits the nucleus of an atom.

Quantized

Describing a phenomenon where values or quantities can only exist in discrete amounts.

Principal Quantum Number (n)

A quantum number that determines the energy level of an electron and its distance from the nucleus.

Azimuthal Quantum Number (l)

A quantum number that describes the shape of an orbital.

Magnetic Quantum Number (m₁)

A quantum number that describes the orientation of an orbital in space.

Spin Quantum Number (mₛ)

A quantum number that represents the intrinsic spin of an electron.

Orbital Diagram

A graphical representation of the arrangement of electrons within an atom.

Electronic Configuration

The distribution of electrons in an atom's orbitals.

Valence Electrons

Electrons in the outer shell of an atom that are involved in chemical bonding.

Nuclear Model

A model proposed by Ernest Rutherford suggesting that an atom has a dense central nucleus surrounded by electrons.