unit 3 kkq predictions

spectroscopy

ability to disperse light into brightness as a function of wavelength

what is kirchoff’s spectrums of light in spectroscopy

1. continuous spectrum- light emitted form a hot and dense matter, featuring unbroken light across all wavelengths

2.emission spectrum- light emitted from a warm, low density gas, featuring distinct, bright lines at specific wavelengths

3.absorption spectrum- light emitted from passing through a cool, low-density gas, featuring dark lines over a continuous background.

key. hot dense interior just below a star’s photosphere (aka atmosphere) emits a __________ blackbody spectrum

continuous

the thin photosphere is _____ on the outside due to _______ to space, it can absorb light from a ______ stellar interior

cooler, energy loss, warmer

what is the cause of spectral features (emission / absorption lines)

interaction between (radiative) energy and atoms/molecules.

key: specific energy photons will interact with atoms and produce features at a corresponding discrete _________

wavelength

balmer lines

visible wavelength hydrogen spectral lines

when Bohr modeled the Hydrogen atom, he used a semi-classical approach. what two aspects were not like classical physics?

1.angular momenta of the electron orbits were quantized. it’s restricted to discrete, quantized integer multiples of Planck's reduced constant where n = principal quantum number.

2.an orbiting (accelerating) electron doesn’t emit light as Maxwell’s classical laws of E&M dictate. Electrons can revolve only in specific orbits without radiating energy. Light is emitted or absorbed only when an electron makes a discrete transition between two levels.

quantized energy levels

Discrete energy states of bound electrons where transitions emit or absorb photons with ΔE=hf.

explain reading an energy level diagram and how an atom can transition between them

each energy level has a discrete E. the most bound level is n=1. an excited H atom can either absorb photons to transition to n>3 (H*_n=3) or emit a photon of a certain energy and transition to a lower energy level.

key: an exact change in energy from n to n’ corresponds to _________

exact change in wavelength from n to n’

what are the names of the three main spectral series of electron transitions, their EMS range, and principal quantum number

Lyman (UV, n=1)

Balmer (visible, n=2)

Pashen (IR, n=3)

spontaneous emission

atoms de-excite rapidly back to ground state through emission of photons

key: each hydrogen atom emits a _____ in a ______ direction

photon, random

ion

atom with a charge (non-neutral)

ionization

liberating a previously bound electron from an atom, creating a free electron and an ion

photons with a wavelength shorter than a specific limit (series limit) will do what to an atom

ionize

define the 4 lines of the Balmer series including the wavelength

656 nm (Hα), 486 nm (Hβ), 434 nm (Hγ), 410 nm (Hδ)