Chem Chapter 2 Flashcards

Flashcards covering key concepts from the 'Quantum Mechanical Model of the Atom' lecture, including atomic models, light-energy connections, quantum theory, the photoelectric effect, wave-particle duality, and quantum numbers defining atomic orbitals.

Plum Pudding Model

An atomic model proposed by J.J. Thompson (1904) consisting of positively charged matter with negatively charged electrons embedded within it.

Nuclear Model

An atomic model proposed by Earnest Rutherford (1911) depicting a central nucleus containing protons, with electrons orbiting it.

Bohr Model

An atomic model proposed by Niels Bohr (1913) where electrons orbit the nucleus in specific energy levels, absorbing or emitting energy during transitions.

Quantum Mechanical Model

An atomic model proposed by Erwin Schrödinger (1920s) that focuses on the wave-like properties of the electron.

Diffraction Patterns

Constructive and destructive interference patterns shown by light, indicative of its classical wave view.

Spectral Line Patterns

Unique patterns produced by atoms interacting with light at specific frequencies, like fingerprints.

Ultraviolet Catastrophe

A prediction by classical physics that hot objects should emit infinite energy at short wavelengths, which experiments disproved.

Quantized Energy

The concept proposed by Max Planck (1900) that light energy is divided into packets.

Quanta

Packets of light energy, as proposed by Max Planck.

Quantum Theory

A revolutionary idea launched by Max Planck's proposal that light energy is quantized.

Photoelectric Effect

A phenomenon where electrons are ejected from a metal surface when light shines on it, where classic wave theory fails to match observations.

Work Function

The minimum energy needed to eject electrons from a metal.

Wave-Particle Duality

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

Double Slit Experiment

An experiment demonstrating that electrons behave like waves by producing an interference pattern, rather than just two bright spots as expected for particles.

Emission Spectrum

Light emitted from an excited atom.

Absorption Spectrum

Missing wavelengths observed when white light passes through a sample.

Heisenberg Uncertainty Principle

The principle that it is impossible to know precisely where an electron is and what path it follows, as the act of determining its position causes it to move.

Wave Equation

A mathematical model of the atom (developed by Schrödinger) focusing on the wave-like properties of the electron.

Wave Function (Ψ)

A possible solution to the wave equation, also called an atomic orbital, with a particular energy associated with it.

Atomic Orbital

A wave function (Ψ) that represents a region of space with a high likelihood for finding an electron.

Probability Density (Ψ²)

A term derived from the wave function (Ψ) which gives a positional probability distribution for finding an electron.

Quantum Numbers

A unique combination of three integers (n, l, ml) that characterize each wave function or orbital, with a fourth (ms) describing electron spin.

Principal Quantum Number (n)

A quantum number that defines the energy, shape, and orientation in space of orbitals, determining the orbital's energy and size.

Angular Momentum Quantum Number (l)

A quantum number that defines the shape of an orbital.

Magnetic Quantum Number (ml)

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

Spin Quantum Number (ms)

A quantum number that describes the spin of the electron, with two possible values: +1/2 and -1/2.

s orbital

An atomic orbital (l=0) that is spherical in shape and is the lowest energy orbital in a shell.

Nodes

Regions within an orbital where there is no probability of finding an electron.

p orbital

An atomic orbital (l=1) that has a two-lobed shape and exists in three orientations (px, py, pz) for n = 2 and above.

d orbital

An atomic orbital (l=2) that mostly has a 4-lobed shape, with five such orbitals existing for n = 3 and above.

f orbital

An atomic orbital (l=3) that mostly has an 8-lobed shape, with seven such orbitals existing for n = 4 and above.