describe how a bright line spectrum is created in terms of power transitions the the electron in an atom together they move from one energy level to another Qualitatively relate the energy of digital transitions come the details colors of light observed. Accurately determine the existence of an facet in an unknown mixture by compare the emission spectrum the a mixture v the emissions spectrum of details element.

You are watching: The characteristic bright-line spectrum of an element occurs when electrons

Resources irradiate emission information from the lab for particular elements modern Chemistry, pp.

Prerequisites Bohr version of the atom, visible irradiate spectrum colors

Vocabulary In the room below, define ground state, excited state, spectral lines, heat emission spectrum

Model 1: production of an emission Spectrum

����������� InBohr�s atomic version an atom�s electrons room assigned to particular energylevels.� The atom is in its floor statewhen the electrons accounting the lowest feasible energy levels.� as soon as an electron absorbs sufficient energyit moves to a greater energy level to create an excited state.� once the electron releases the energy, itdrops earlier to a lower power level.� theenergy is released in the type of light!�The wavelength the the light indicates the difference in between the energyof these 2 levels.� every wavelength oflight coincides to a particular color of irradiate (which may or might not be in thevisible area the the spectrum).�Consequently, atoms emit a characteristic collection of discrete wavelengths,not a continuous spectrum.

Since each aspect hasits own distinct electron arrangement, the light that is emitted by the atomsproduces an emission spectrum that have the right to be supplied to determine the element.� In other words, an atomic spectrum deserve to be usedas a �fingerprint� because that an aspect because it is distinctive for each element andreflects the energy levels lived in by the electrons in an atom of the element.

Task:

First, determine what shade is observed because that eachof the gas samples below.

Metallic Element

Color that the Flame

Barium

Calcium

Lithium

Potassium

Strontium

Sodium

Key Questions

1. What is the difference between an excited andground state of an atom?

2. What happens when electrons relocate from theexcited state come the ground state?

3. What colors of visible irradiate are found in theemission spectrum the hydrogen?

Model 2:� power Level diagram forthe Hydrogen Atom


If atoms only emit discrete wavelengths of light,then one atom�s power levls deserve to only have discrete energies.� The power level diagram listed below illustratessome of the power levels uncovered in a hydrogen atom, through arrows reflecting thecorresponding electron transitions that develop its clearly shows emissionspectrum.� The transitions shown arefrom excited claims to the 2nd energy level.� Transitions to ground state execute not fall in the visible range.

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Key Questions

4. What wake up to the energy of the electron toproduce the it was observed spectral lines?

5. Because that the facet hydrogen, which color(wavelength) of irradiate is produced by the largest power drop the anelectron?� define your answer (based onthe model).

6. Which color of light is developed by thesmallest power drop of an electron?�Explain her answer.

7. Why do different aspects emit various colorsof light?

EXTRA CREDIT!

8. In model 2, every one of the transitions prevent atn=2.� If a shift were to be shownin the diagram, would you expect the light to be in the infrared or ultravioletregion that the spectrum?� describe youranswer.

Problems:

1. Below are the bright line spectra that fourelements and also the spectrum of one unknown gas.

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a) Whichelements space in the unknown?

2. In a forensic investigation, it was suspectedthat the victim was poisoned by a toxicity chemical which consists of the elementcopper and accumulates in big amounts in hair as well as other tissues.� utilizing your understanding of emission spectra,design a an approach by i beg your pardon you can confirm the visibility of this toxin in thevictim.� incorporate the resources andequipment you would must make a definitive determination.