Lecture 4_8-28-25 Light, Quantum Numbers, Orbitals File

Flashcards covering fundamental concepts of light, energy, atomic models (Bohr and Quantum), the photoelectric effect, and quantum numbers.

Energy (E)

A physical quantity with units of J (Joules), related to frequency by E = hν and to wavelength by E = hc/λ.

Planck's Constant (h)

A fundamental physical constant with a value of 6.626 x 10^-34 J•s, used in energy calculations for photons.

Frequency (ν)

The number of waves passing a point per unit time, measured in s^-1 or Hz. High frequency corresponds to high energy.

Speed of Light (c)

A fundamental physical constant with a value of 3.00 x 10^8 m/s, defining the relationship between wavelength and frequency (c = λν).

Wavelength (λ)

The spatial period of a periodic wave, measured in meters (m). Long wavelength corresponds to low energy.

Photoelectric Effect

The phenomenon where electrons are ejected from a metal surface when light shines on it, but only if the light's energy (frequency) is above a certain threshold.

Photon

A massless particle (quantum) of light or other electromagnetic radiation, carrying quantized energy.

Quantized Energy

Energy that exists in discrete, specific amounts rather than a continuous spectrum.

Targeted Action of Therapeutics

A strategy to improve drug safety and efficacy by precisely controlling when, where, and how much drug is delivered, reducing side-effects and increasing potency.

Photon Emission

The process where excited elements release energy in the form of discrete frequencies of light, demonstrating quantized atomic behavior.

Bohr's Model of the Atom

A model stating that electrons orbit the nucleus in specific, quantized radii (allowed energy states). Closer orbits have lower energy and are more stable.

Electron Absorption

The process where an electron gains energy (e.g., from a photon) and moves from a lower energy level to a higher energy level.

Electron Emission

The process where an electron loses energy (e.g., by emitting a photon) and moves from a higher energy level to a lower energy level.

Wave-Particle Duality

The concept that light and matter (like electrons) exhibit both wave-like and particle-like properties.

Quantum Theory's Model of the Atom

The current atomic model treating electrons as waves, defining their energy and orbitals using a set of quantum numbers.

Orbitals

Regions of space around the nucleus where an electron is most likely to be found, defined by mathematical solutions in quantum theory.

Quantum Numbers

A set of numbers (n, l, ml, ms) that describe the properties of electrons and the orbitals they occupy; no two electrons can have the same four quantum numbers.

Principal Quantum Number (n)

A non-zero positive integer (1, 2, 3, etc.) that describes the electron's distance from the nucleus (orbital size) and is the primary determinant of its energy. Higher n means higher energy.

Angular Momentum Quantum Number (l)

An integer value from 0 up to (n-1) that is the secondary determinant of an electron's energy and describes the shape of an orbital (related to the number of nodal planes).

Nodal Plane

A region within an orbital where an electron has zero probability of being found.

Magnetic Quantum Number (ml)

An integer value from -l to 0 to +l that determines the spatial orientation of an orbital. The number of possible ml values indicates the number of orbitals in a given sublevel.

Orbital Capacity

Each atomic orbital can hold a maximum of two electrons.