Atomic Spectra and Structure

Flashcards covering the basic structure of an atom, the concept of ions and ionization, electron energy levels, hydrogen spectral series (Lyman, Balmer, Paschen), and types of spectra (continuous, absorption, emission) used by astronomers.

Bohr model of an atom

A model used to understand why atoms emit and absorb light, explaining observations even though it's not entirely correct.

Nucleus

The core of an atom where almost all of its mass resides, containing protons and neutrons.

Protons

Positively charged particles located in the nucleus, whose number determines the element.

Neutrons

Neutrally charged particles located in the nucleus, whose number determines the isotope of an element.

Electrons

Negatively charged particles that orbit the nucleus; their movement causes atoms to absorb or emit energy.

Ground state

The lowest allowed energy state of an atom, where electrons are as close to the nucleus as quantum mechanics allows.

Discrete energy levels

Specific distances or energy amounts at which electrons are allowed to orbit the nucleus, similar to rungs on a ladder.

Ionized atom / Ion

An atom that has absorbed enough energy to lose an electron, resulting in a net electrical charge.

Photon

A particle of light; its energy determines its wavelength.

Electron absorption of energy

When an electron absorbs a photon of just the right energy, causing it to jump to a higher permitted energy level.

Electron emission of energy

When an electron jumps from a higher energy level to a lower one, releasing a photon of energy.

Lyman series

A group of UV wavelengths (91nm - 122nm) associated with electron jumps to and from the n=1 energy level in hydrogen.

Balmer series

A group of visible and UV wavelengths (365nm - 656nm) associated with electron jumps to and from the n=2 energy level in hydrogen.

Paschen series

A group of IR wavelengths (820nm - 1875nm) associated with electron jumps to and from the n=3 energy level in hydrogen.

Hydrogen spectra

The unique pattern of wavelengths of light emitted or absorbed by hydrogen, crucial for understanding the universe's most abundant element.

Ha (Hydrogen Alpha)

A red hydrogen Balmer line at 656 nm.

Hb (Hydrogen Beta)

A blue-green hydrogen Balmer line at 486 nm.

Hg (Hydrogen Gamma)

A blue hydrogen Balmer line at 434 nm.

Hd (Hydrogen Delta)

A violet hydrogen Balmer line at 410 nm.

Spectra as identification

Unique patterns of spectral lines for different elements, used by astronomers like a fingerprint to determine chemical composition.

Continuous spectrum

Light from a hot, dense source that shows all wavelengths without interruption.

Absorption spectrum

Light that has passed through a low-density gas, showing specific dark lines where wavelengths were absorbed by the gas.

Emission spectrum

Light emitted by a low-density gas itself, showing specific bright lines at the wavelengths it re-emits.

Line spectra

The characteristic patterns of bright or dark lines in emission or absorption spectra that reveal the chemical composition of a gas.