Quantum Theory and the Electronic Structure of Atoms

Flashcards covering key vocabulary and concepts from the lecture on Quantum Theory and the Electronic Structure of Atoms, including types of energy, light properties, quantum theory, and atomic emission.

Energy

The capacity to do work or transfer heat.

Kinetic Energy

Energy that results from motion.

Thermal Energy

Energy associated with the random motion of atoms and molecules.

Potential Energy

Energy possessed by an object due to its position.

Chemical Energy

Energy stored within the structural units of chemical substances.

Electrostatic Energy

Potential energy that results from the interaction of charged particles, directly proportional to the product of the charges (Q1Q2) and inversely proportional to the distance (d) between them (Eel ∝ Q1Q2/d).

Law of Conservation of Energy

Energy can neither be created nor destroyed.

Wavelength (λ)

The distance between two consecutive peaks or troughs of a wave.

Frequency (ν)

The number of cycles or waves per second, measured in Hertz (Hz) or inverse seconds (s^-1).

Speed of Light (c)

A constant (3.00 × 10^8 m/s) that relates wavelength and frequency of electromagnetic radiation by the equation c = λν.

Young's Double Slit Experiment

An experiment performed in 1801-03 by Thomas Young, demonstrating the wave nature of light through interference patterns.

Amplitude

The maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position.

Blackbody

A theoretical object that absorbs all incident electromagnetic radiation and emits light only due to its temperature, without reflecting any.

Max Planck's Quantum Theory

States that radiant energy can only be absorbed and released in specific discrete units called quanta, not in continuous amounts.

Quantized Energy (Planck's Equation)

The energy (E) of a quantum is directly proportional to its frequency (ν) by the equation E = hν, where h is Planck's constant.

Planck's constant (h)

A fundamental physical constant, approximately 6.63 × 10^-34 J·s, used to relate the energy of a photon to its frequency.

Photoelectric Effect

The phenomenon where electrons are ejected from a metal surface when exposed to electromagnetic radiation of a sufficient minimum frequency (threshold frequency).

Dual-Nature of Light

The concept that light exhibits both wave-like and particle-like properties (as photons).

Photon

A quantum of light, representing an elementary particle of electromagnetic radiation.

Binding Energy (BE) / Work Function (W)

The minimum amount of energy required to remove an electron from a metal surface in the photoelectric effect.

Kinetic Energy of Ejected Electron (KE)

The energy of an electron ejected by the photoelectric effect, calculated as KE = hν - BE (where hν is the energy of the incident light and BE is the binding energy).

Continuous Spectrum

A spectrum that contains all wavelengths of visible light, appearing as a continuous band of colors, like a rainbow.

Line Spectrum

A spectrum consisting of distinct, separated colored lines, produced when excited atoms emit light at specific discrete wavelengths.

Bohr's Hypothesis (Quantization of Atoms)

The theory stating that electrons in an atom reside in specific orbits, each with a defined radius and energy state, and can only move between these 'allowed' energy states.

Ground State

The lowest possible energy state of an atom, where its electrons occupy the closest orbits to the nucleus.

Excited State

A higher energy state an atom reaches when its electrons absorb external energy and transition to orbits further from the nucleus.

Relaxation (Atomic)

The process where an electron in an excited state falls back to a lower energy state, releasing the absorbed energy as a photon.

Photon Emission (from atoms)

The release of a photon of light by an atom when an electron transitions from a higher energy level (excited state) to a lower energy level, with the wavelength of the emitted light related to the energy difference (ΔE = hc/λ).