1. Unit 3: Identifying elements and molecules Unit Objectives: Explain how mass spectrometry is used to identify different substances. Deduce the identify of a compound or molecules using fragment analysis of mass spectra. Determine the identify of the alloy used in pennies by finding density using the displacement method. Calculate the percent error in your experimental values. Determine the identify of metals present in salts using the flame test method and apply previous learned skills to calculate the frequencies and energy of light you observe.

2. How do scientists identify elements and molecules? Brainstorm with a partner. Think of as many answers that you can. You may use your textbook and notes as reference.

3. Mass Spectrometry

4. Today’s objectives Define Mass Spectrometry Label and identify parts on a mass spectrometer Understand what a mass spectrometer measures Analyze fragment patterns on a mass spectrum

5. My job at Agilent: help work on a GC-MS (gas chromatograph-mass spectrometer) that can quickly analyze samples and accurately detect and identify which molecules are present in that sample. Why is the machine important for science and society? Detecting Dangerous pollutants in the air Drug testing Crime Scene Analysis Used on robotic aircraft to detect atmosphere composition of Mars and Titan GC-MS

6. Detecting Molecules and elements requires advanced technology that is capable of identifying very very small things….. How small?

7. 1 meter Guitar Length: 1 meter Fingernail: 1 centimeter (.01 meters)

8. What’s the Big Deal? 8 How small is nanometer? 1.0 x 10 -9 m What’s the Big Deal? http://be.agilent.com/company/facts/profile.shtml

9. Earth at 1,000 Million Meters in Space 10 9 9 © B. Bryson http://be.agilent.com/company/facts/profile.shtml

10. Continents Visible at 100 Million Meters 10 8 10 http://be.agilent.com/company/facts/profile.shtml

11. California at 10 Million Meters 10 7 11 http://be.agilent.com/company/facts/profile.shtml

12. San Francisco Peninsula at 1 Million Meters 10 6 12 http://be.agilent.com/company/facts/profile.shtml

13. City of San Francisco at 100,000 Meters 10 5 13

14. Golden Gate Park at 10,000 Meters 10 4 14 http://be.agilent.com/company/facts/profile.shtml

15. Buildings in Golden Gate Park at 1,000 Meters 10 3 15 http://be.agilent.com/company/facts/profile.shtml

16. Japanese Tea Garden at 100 Meters 10 2 16

17. Pond in Japanese Tea Garden at 10 Meters 10 1 17 http://be.agilent.com/company/facts/profile.shtml

18. Flowers in Pond at 1 Meter Outer Space Inner Space 10 9 10 -9 18 http://be.agilent.com/company/facts/profile.shtml

19. Flower with Bee at 0.1 Meter 10 -1 19 http://be.agilent.com/company/facts/profile.shtml

20. Eye of Bee at 0.01 Meter 10 -2 20 http://be.agilent.com/company/facts/profile.shtml

21. Pollen on Eye of Bee at 0.001 Meter 10 -3 21 http://be.agilent.com/company/facts/profile.shtml

22. Structure of Pollen at 0.0001 Meter 10 -4 22 http://be.agilent.com/company/facts/profile.shtml

23. Bacteria on Pollen at 0.00001 Meter 10 -5 23 http://be.agilent.com/company/facts/profile.shtml

24. Virus Particle on Bacteria at 0.000001 Meter 10 -6 24 http://be.agilent.com/company/facts/profile.shtml

25. Close-up Virus Particle at 0.0000001 Meter 10 -7 25 http://be.agilent.com/company/facts/profile.shtml

26. DNA Molecules from 0.00000001 Meter 10 -8 26 http://be.agilent.com/company/facts/profile.shtml

27. Width of DNA Molecule at 0.000000001 Meter 10 -9 1 nanometer 27 http://be.agilent.com/company/facts/profile.shtml

28. Brainstorm with a partner: Why do we need to be able to identify things we can’t see with the naked eye?

29. Pictures and text from http://be.agilent.com/company/facts/profile.s html

30. Mass Spectrometry http://www.youtube.com/watch?v=EzvQzImB uq8 http://www.youtube.com/watch?v=EzvQzImB uq8 http://www.youtube.com/watch?v=tOGM2gO HKPc http://www.youtube.com/watch?v=tOGM2gO HKPc What are the four key steps used in mass spectrometry to identify a substance? What phase of matter can it measure?

31. Pictures and text from

32. 4 Key Processes in a Mass Spectrometer 1) Ionization: high voltage electron gun fires a beam of high energy electrons into a vaporized sample. This causes the atoms to form positive ions. (cations) 2) Acceleration: Negative plates accelerate the positive ions down the tube 3) Deflection: A magnetic field deflects the ions so that they are separated—lighter ones bend more than heavier ones 5) Detection: The detection system generates an electrical current when ions hit it. The strengths of the electrical signal are sent to a computer for analysis. Molecules are plotted on a graph as m/z (mass/ion charge).

33. How mass spectrometry works With a partner, name the process taking place at A, B, C, and D.

34. On the diagram, sketch the path of the following ions under the same conditions: 24 Na + ion labelled P 23 Na + ion labelled Q 25 Na + ion labelled R Explain why it would not be possible to distinguish between 24 Mg + and 48 Ti 2+ ions in a low resolution mass spectrometer.

35. Gas Chromatograph-Mass Spectrometer (GC-MS) Mass spectrometer

37. Mass Spec Vocabulary 1.Mass spectrometry: analytical technique used to determine the chemical identity of substances in a sample. 2.Mass spectrometer: device used to carry out mass spectrometry. Some mass spectrometers can sit on a tabletop, others are MUCH bigger. 3.Mass spectrum: The output of a mass spectrometer. A mass spectrum looks a bit like a line graph with different peaks. 4.Mass spectrometrist: A scientist who specializes in mass spectrometry. 5.Analyte: substance being analyzed in the mass spectrometer 6.Base Peak: The most abundant analyte—it can be just an element or an ion of the molecule itself. If it is a molecule, then all other fragments are fragments of that molecule.

38. How to read a mass spectrum –Ex. A Sometimes the fragments can be isotopes of the same elements, or a molecule that has broken apart in the ionization process. IN this example, the lines represent an _______________of ___________. How many ________________of _____________are there? Label each fragment. What line is the most abundant? What line does this represent? Fragmentation Patterns Base Peak

39. How to read a mass spectrum –Ex. B How many fragments are in spectra “B”? What is the identity of each fragment? Label on the graph Which isotope is the most abundant? What is the formula for the molecule that is present? How many isotopes are there for the element that makes up this molecule?

40. How to read a mass spectrum –Ex. F How many fragments are in spectra “F”? What is the identity of each fragment? Label the graph How many isotopes are there for this element? Which isotope is the most abundant? What is the formula for the molecule that is present?

41. Your turn! DO letter C,E,D (12 min) When finished, look so I know you are done. IF you need help, raise your hand.

42. Day 1-Exit Slip Answer using your notes: 1)What does mass spectrometry measure? 2)What do we use it for? 3)What are the 4 key processes of a mass spectrometer? 4)What do the lines represent on a mass spectrum? What do the lines tell you? 5)Which molecule is represented by the fragment below?