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Electrons Arrangement in the Atom Key words: Energy, wavelength, frequency, photon Use these terms in a sentence (s) which makes sense.

Electrons

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Electrons. Arrangement in the Atom Key words: Energy, wavelength, frequency, photon Use these terms in a sentence (s) which makes sense. . Objectives. - PowerPoint PPT Presentation

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Page 1: Electrons

ElectronsArrangement in the AtomKey words: Energy, wavelength, frequency, photon

Use these terms in a sentence (s) which makes sense.

Page 2: Electrons

Objectives• To use the “Bohr Model for Hydrogen Atom”

and “Electromagnetic Spectrum” diagrams from the Reference Tables to relate color, frequency, and wavelength of the light emitted to the energy of the photon.

• To understand the inverse relationship between wavelength and frequency, and the direct relationship between energy and frequency.

Page 3: Electrons

Electrons will give off electromagnetic radiation

-When “energized” by heat, electricity, light or chemical reactions.

How and why does this happen?

Page 4: Electrons

Energy exists in photonsA photon has a specific amount

(or packet) of energyAlso use the word “quantum of

energy”

Photons with different energy will have specific wavelengths related to the energy

Page 5: Electrons

Bohr’s model

Page 6: Electrons

Bohr’s Model of the AtomElectrons orbit the nucleus at:At the lowest energy level possibleCalled the ground state

Electrons can be excited by:Electricity, light, chemical reactions

When excited, an electron will absorb only a certain amount of energy,

A “packet” of energy called a photon or quantum

Page 7: Electrons

Bohr’s model

Page 8: Electrons

Bohr’s modelWhen excited, the electronWill jump to a higher energy

level ◦Called the excited state

The electron does not stay in the excited state but falls back toward the nucleus and releases energy

Page 9: Electrons
Page 10: Electrons

Bohr provided critical information Ground vs. excited state

Number of electrons that exist at specific energy levels

Bohr’s model works for hydrogen but not for the complex atoms

Page 11: Electrons

Emission Spectrum LabPurpose: To relate the unique emission spectra lines of an element to the energy levels of the atom.

Essential Question: What are the emission spectra for specific elements?

Page 12: Electrons

This is?

Page 13: Electrons

How do neon lights produce the glowing colors? FACTS: Neon is a colorless, inert (non-

reactive, non-flammable) gas

Neon lights are tubes filled with neon gas.

Page 14: Electrons

Neon atomsNormal conditions

◦Electrons are at the ground state◦No light (energy) is emitted

Electricity passing through the tube◦Atoms absorb energy◦Electrons become excited and

unstable◦Electrons are pulled back toward the

nucleus◦Electromagnetic radiation is emitted

Page 15: Electrons

Elements and their electromagnetic radiationEmissions spectrumUnique for each element Electrons are excited by

electricity When they are pulled back by the

____________, they give off __________

Page 16: Electrons

Emission SpectrumWhite light

◦Write the order of the colors

Hydrogen: Nitrogen:Mercury:Neon:Other:

Page 17: Electrons

Emission Line Spectra

Page 18: Electrons

Emissions Spectra - Simulationhttp://phet.colorado.edu/en/simul

ation/discharge-lamps

Produce light by bombarding atoms with electrons. See how the characteristic spectra of different elements are produced, and configure your own element's energy states to produce light of different colors.

Page 19: Electrons

Emission SpectraUnique for each elementUsed to identify elements as part

of unknown compounds

Page 20: Electrons

Hubble Space Telescope