Hydrogen Spectra and Wave-Particle Duality (2.1) - Vocabulary Flashcards

A set of vocabulary-style flashcards covering key terms from the hydrogen spectra and quantum mechanics lecture notes.

Hydrogen spectra

The characteristic lines produced when hydrogen atoms transition between energy levels, observed as emission or absorption at specific wavelengths.

Emission spectrum

The bright-line spectrum produced when excited atoms emit photons as electrons drop to lower energy levels.

Visible spectrum

The portion of electromagnetic light visible to the human eye, roughly 400–700 nm.

Balmer series

Hydrogen emission lines from transitions to n=2, lying in the visible region.

Lyman series

Hydrogen emission lines from transitions to n=1, lying in the ultraviolet region.

Paschen series

Hydrogen emission lines from transitions to n=3, lying in the infrared region.

Bohr model

Early atomic model with quantized electron orbits around the nucleus, explaining discrete spectral lines.

Energy level

A fixed, quantized energy value that electrons can occupy in an atom.

Photon

A quantum of light carrying energy E = hν, emitted or absorbed during electronic transitions.

Excited state

A higher energy state of an electron than the ground state; transitions from here emit photons.

Ground state

The lowest energy state of an atom (n=1 for hydrogen in many discussions).

Wavelength (λ)

Distance between successive wave crests; related to energy and spectral lines.

Ultraviolet light

Electromagnetic radiation with shorter wavelengths than visible light; includes high-energy hydrogen lines (e.g., transitions to n=1).

Infrared light

Electromagnetic radiation with longer wavelengths than visible light; includes hydrogen lines from transitions to higher n (e.g., Paschen system).

Rydberg constant

R_H ≈ 1.097 × 10^7 m⁻¹; used in formulas for hydrogen spectral lines.

Principal quantum number (n)

Integer labeling electron energy levels in atoms (n = 1, 2, 3, …).

ΔE energy difference

Energy change between two levels during a transition; determines the photon’s energy and wavelength.

Absorption

Process by which a system gains energy by taking in a photon.

Double Slit Experiment

Classic experiment showing diffraction and interference, illustrating wave behavior of light and matter.

Wave-Particle duality

Idea that particles and waves exhibit both wave-like and particle-like properties.

De Broglie

Hypothesis that matter has wave-like properties; relates wavelength to momentum (λ = h/p).

Planck’s constant

h ≈ 6.626 × 10⁻³⁴ J·s; relates energy and frequency (E = hν) and appears in de Broglie’s relation.

Standing waves

Non-propagating wave patterns that can occur at discrete frequencies; electrons in atoms behave like standing waves.

Orbitals

Regions in space with high probability of finding an electron; described by Ψ² (probability density).

Schrödinger’s equation

Fundamental equation of quantum mechanics used to calculate orbitals and electron probabilities.