The presence of spectral lines is explained by
quantum mechanics
in terms of the energy levels of atoms, ions and molecules. … This causes an electron to be promoted into a higher energy level, and the atom, element or molecule is said to be in an excited state.
What causes the lines in the emission spectrum for elements quizlet?
What causes lines in an atomic emission spectra?
When a sample is heated, electrons are excited up to higher energy levels
. … Electrons drop to lower energy levels which emits light energy. Several transitions occur to the same energy level which forms a series of lines.
What produces the colored lines in an emission spectrum for an element?
Flame tests are useful because
gas excitations
produce a signature line emission spectrum for an element. … When the atoms of a gas or vapor are excited, for instance by heating or by applying an electrical field, their electrons are able to move from their ground state to higher energy levels.
How is an emission spectrum formed?
How an Emission Spectrum Is Produced.
When an atom or molecule absorbs energy, electrons are bumped into a higher energy state
. When the electron drops to a lower energy state, a photon is released equal to the energy between the two states. … 27, 2020, thoughtco.com/definition-of-emission-spectrum-605081.
What is an emission line spectrum quizlet?
Emission spectra are
produced when photons are emitted from atoms as excited electrons return to a lower energy level
. describe the electromagnetic spec. – electromagnetic radiation comes in different forms. – All forms travel at the same speed of light but have different wavelengths.
What causes the dark lines in the absorption spectrum of an element to occur?
An absorption spectrum occurs when light passes through a cold, dilute gas and atoms in the gas absorb at characteristic frequencies;
since the re-emitted light is unlikely to be emitted in the same direction as the absorbed photon
, this gives rise to dark lines (absence of light) in the spectrum.
What causes the lines in these spectra Why are the colors of the lines different?
The different colors are a result of
varying energies of transition for different states
. Hydrogen has only a single transition while calcium has multiple transitions resulting in more complicated spectral lines.
Why elements produce different numbers of spectral lines?
Each element has its own unique line spectrum and is thus referred to as the “fingerprint” for a particular element. The spectra for each element are unique because
each element contains differing numbers of electrons and thus different energy levels
.
What causes the black lines in absorption spectra quizlet?
Absorption lines are produced when
a certain element or molecule is hit with a light, absorbs that light
, yielding an absorption spectra with black lines indicating where no light gets through to the element. When the electron jumps up it must absorb that same frequency photon in order to do so.
What are absorption lines in a spectrum?
An absorption line will appear in a spectrum
if an absorbing material is placed between a source and the observer
. This is seen in the spectra of stars, where gas (mostly hydrogen) in the outer layers of the star absorbs some of the light from the underlying thermal blackbody spectrum. …
How are spectral lines formed quizlet?
When an electron falls from higher to lower energy level, it emits a photon of energy that is equal to the difference in energy between two levels
. Hence, only photons of specific energies which correspond to specific wavelengths are emitted, giving rise to an emission line spectrum.
Why does each element produce a unique atomic emission spectrum?
Different elements have different spectra because
they have different numbers of protons, and different numbers and arrangements of electrons
. The differences in spectra reflect the differences in the amount of energy that the atoms absorb or give off when their electrons move between energy levels.
How are line spectrums formed chemistry?
It is created
when the electrons in an atom return from a higher (excited) state to lower energy levels
, thereby emitting energy.
How the different types of spectra are generated?
| Balmer line Wavelength (nm) | Hγ 434.1 | Hδ 410.2 | Hε 397.0 |
|---|
What causes the black lines that are seen in the absorption spectra of gases like hydrogen and helium?
When light passes through gas in the atmosphere some of the light at particular wavelengths is scattered resulting in darker bands
. These lines came to be known as ‘spectral lines’ and were cataloged by heating common elements until they produced light and measuring the wavelengths emitted.
What do the bright lines in the spectra represent?
What do the individual lines in a bright line emission spectrum represent? They represent
the wavelengths of light that is absorbed by the spectrum
They represent the energy that the atom gives off when their electrons are in place.
What causes the emission of radiant energy that produces characteristic spectral lines?
When electrons move from a higher energy level to a lower one, photons
are emitted, and an emission line can be seen in the spectrum.
What is an absorption line spectrum quizlet?
absorption spectrum. spectrum that appears
to have dark lines against a continuous spectrum
, which the dark lines are this spectrum; electrons of a cooled gas go from low to high energy. absorption.
Why are spectral lines for molecules more complex than lines from elements?
Much like atoms, molecules can exist only in certain well-defined energy states, and again like atoms, molecules produce emission or absorption spectral lines when they make a transition from one state to another. Because molecules are more complex than atoms,
the rules of molecular physics
are also much more complex.
The lines on the spectrum correspond
to the frequencies of photons of light emitted
. Electrons in atoms only absorb and emit energy in certain discrete amounts, the energy absorbed is quantised.
What is line spectra example?
The light that is being emitted from the clock radio produces a continuous spectrum. … The lines on a spectrum are determined by the movement of electrons in energy levels. An example of a line spectrum is
an exit sign
. An example of a continuous spectrum is a clock radio.
How are absorption lines produced?
An absorption line is produced
when a photon of just the right energy is absorbed by an atom, kicking an electron to a higher energy orbit
. … Because the energy levels in an element’s atoms are fixed, the size of the outward jumps made by the electrons are the same as the inward jumps.
What are the factors affecting width of spectral lines?
- Widths of Spectral Lines (continued)
- Pressure Broadening. This cause of line broadening may be regarded as being due to random collisions between atoms, which disturb internal interactions and shorten the lifetime. …
- Doppler Broadening. …
- Absorption of Radiation and Absorption Coefficients.
Which light source produced both a continuous and a line spectrum?
The spectrum of
a fluorescent light
has bright lines and a continuous spectrum.
What produces a continuous spectrum?
Continuous spectra (also called thermal or blackbody spectra) arise
from dense gases or solid objects which radiate heat
. They emit radiation over a broad range of wavelengths, thus the spectra appear smooth and continuous.
How does a spectroscope produce a continuous spectrum quizlet?
Continuous spectra is where the sun and heated solids emit radiation that contain all frequencies, and line spectra are produced by
excited atoms in the gas phase
, and contain only certain frequencies.
How are spectral lines both emission and absorption are formed?
Emission and absorption lines are also seen
when oppositely charged ions recombine to an electrically neutral state
. The thus formed neutral atom is highly excited, with electrons transitioning between states, emitting and absorbing photons. The resulting emission and absorp-tion lines are called recombination lines.
What would most likely generate an emission line spectrum?
An emission line will appear in a spectrum if
the source emits specific wavelengths of radiation
. The sun and a light bulb more or less emit white light which composed of multiple wavelengths of light. … a neon light or laser is has a specific wavelength depending on the color.
How are spectral lines used by scientists?
From spectral lines astronomers
can determine not only the element, but the temperature and density of that element in the star
. The spectral line also can tell us about any magnetic field of the star. … The light from the stuff between the stars allows astronomers to study the interstellar medium (ISM).
