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Published byMorgan Strickland Modified over 6 years ago
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On the white boards Draw out the basic structure of an atom Add labels
Annotate to show what happens an element is heated and gives off a colour
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Electron Orbits and Spectrometers
Draw a line under last lesson’s work and write today’s title in your book... 21/11/2018 c/w Electron Orbits and Spectrometers
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Energy Levels Electrons around an atom can only exist in discrete electron shells that have specific energy levels The further out a shell, the higher the energy. If an electron absorbs energy it will move to an outer shell Electrons then drop back down and emit the energy as a photon (a light particle) of specific wavelength
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Different Elements Zinc Put these flames in order of their position in the Electromagnetic spectrum (long to short wavelength) Potassium What might this tell us about the energy needed to excite an electron inside the atom? Strontium Strontium, sodium, zinc, copper, potassium Energy needed to excite potassium is the most as it has the shortest wavelength Sodium Shorter wavelength = Higher Energy! Copper
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Emission Spectra An unknown solid is heated and produces a spectra. Deduce which element it is made up of Why do these emission spectra show discrete bands of colour? Made of strontium as lines are the same. Different elements have different electron shells therefore there are various specific energy levels that the electrons will jump between, these are equivalent to specific wavelengths and as such a colour. Draw the emission spectra for the following: A compound with both strontium and titanium A compound with manganese and copper
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Placing Telescopes This diagram shows which type of electromagnetic radiation is absorbed by our atmosphere X-rays & gamma Some EM spectrum divisions are strongly absorbed by the atmosphere and as such to view these EM waves from faraway sources eg. A star, you’d have to place the telescope outside of the atmosphere in orbit UV VISIBLE Infrared Microwave Radio waves Why might some of the EM telescopes we use have to be placed in orbit to observe far away stars and galaxies?
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Advantages of having telescopes in space
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Real-life Context: CDs
What is happening in this image? Why is the CD producing this pattern? This is a spectrum produced by the spreading of light when white light hits the surface. The surface is made of lots of little dips and bumps and this causes the white light to split into the individual colours!
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Practice
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Extend 6 mark Exam Question What is meant by an emission spectra and how is it produced? Why do different elements have different spectral readings? [6 marks]
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Swap your book with your partner & mark their answer:
Award 1 mark for each of the following points, to a maximum of 6 marks. An emission spectra shows the energy emitted by a heated element Electrons sit in discrete energy levels When heated, electrons are excited to a higher energy level Electrons then fall back to their original level and emit the energy with a specific wavelength The wavelength corresponds to a specific colour band against a black background As different elements have different numbers of electrons in different positions, the emission lines are different Explain how they could make their work better
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6 mark Exam Questions Identify the parts of the electromagnetic spectrum and discuss how the danger of the spectrum varies Explain why neon lights can appear in a variety of colours Suggest how a scientist could determine the activity and potential danger of a radioactive sample
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Objectives: 6.6 Recall that in an atom the number of protons equals the number of electrons and is therefore neutral 6.7 Recall that in each atom, its electrons orbit the nucleus at different set distances from the nucleus 6.8 Explain that electrons change orbit when there is absorption or emission of electromagnetic radiation 6.9 Explain how atoms may form positive ions by losing outer electrons
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