1. Unit 2 Atomic/Nuclear Theory/Periodic Patterns

2. Unit Sequence DayObjectivesAssessments Activities & Assignments 1 Hook Interest Data & Observations, Gold penny taped in notebook, 1 page story Alchemist’s Dream Lab, Write 1 page story of fictional discovery & consequences 2 Overview of Atomic Theory Fireworks Poster Project Rubric History, Chemistry, Spectra of Fireworks 2 Review basic Atomic Structure Previous knowledge in notes, Completed assignment, Cooperative Quiz Use atomic mass & number to draw Bohr Models of elements 1-18 odd Quiz 3,4,5,6 History of Atomic Theory – Dalton, Thomson, Rutherford, (Emission Spectra & Photoelectric effect) Bohr Lecture discussions, pair questions, Dalton Quiz – Informal, Thomson Quiz, Rutherford quiz, Comparative Quiz Lectures, Cathode Ray Demos, Video Clips, Flame Tests Lab, Emission Spectra

3. Unit Sequence DayObjectivesAssessments Activities & Assignments 7 Isotopes, Avg Atomic Mass, Ions Book questions, Worksheet – Problem Solving to be developed / Quiz 8- 10 Radioactivity- Designing Experiments Lab check points, Graphical sharing on doc viewerk, data & observations in NB Radioactivity Shielding Lab – Practice Day 1, Collect Good Data Day 2, HW: Graph, Share Data Day 3 ½ Lives Graphical Results ½ Life Quiz ½ Lives Blocks ½ Life Problems 11 Types of Radioactivity Informal Quiz Notes & Geiger Counter Demos Book Questions about basics & applications 12 Nuclear Equations Discuss, Review & Quiz Styrofoam balls demo, Write equations for Uranium decay series

4. Unit Sequence DayObjectivesAssessments Activities & Assignments 13 Understand Quantum Mechanics Quiz Partner Book questions, Demo Standing Waves, Video – Orbitals, Slides, Orbitals. 14 Electron Configurations Discuss as show config vs diagram from H  Na, Write configurations 1-35 odd 15 Periodic Patterns of Electron Configurations - Quiz – configs, Noble Gas configurations & drawing Discovery discussion & decorate patterns of periodic table, write Noble Gas configurations of 1-35 odd 16 History of Periodic Table Progress on mystery, discussion feedback, quiz partner Cochran – Periodic Table Mystery, Book questions, Notes on History 17 Patterns of Periodicity - Reactivity, bonding, ions, atomic radius, ionization energy, electronegativity Comparing Periodic Groups Laserdisc demos of radioactivity, decorate bonds & ions on blank, use data to make graphs & interpret patterns Element Samp;e Observations

5. Unit Sequence DayObjectivesAssessments Activities & Assignments 13 Understand Patterns of Atomic Radius & their Basis Rank atoms vertically & horizontally – small to large. Explain trend of each. Find patterns in pictures of radii. Examine Explanation 14 Understand how Periodic Table is organized Periodic Card Set Old Periodic Table Fill in Blank 15 16 17

6. Vocab 2A Atom Atom Law of Definite Proportions Law of Definite Proportions Law of Conservation of Mass Law of Conservation of Mass Cathode ray Cathode ray Cathode ray tube Cathode ray tube Electron Electron Nucleus Nucleus Proton Proton Neutron Neutron Atomic mass unit Atomic mass unit Atomic number Atomic number Atomic mass Atomic mass Ion Ion Isotope Isotope Electromagnetic radiation Electromagnetic radiation frequency frequency Wavelength Wavelength Quantum Quantum Photoelectric effect Photoelectric effect Photon Photon Line spectrum Line spectrum Ground state Ground state Excited state Excited state Quantum mechanical model Quantum mechanical model Orbital Orbital Sublevel Sublevel Electron configuration Electron configuration

7. Vocabulary 2B Isotope nuclear reactor Radioisotope nuclear weapon Radioactivity half life Radiation nuclear equation FissionpositronFusion radiocarbon dating Radioactive decay critical mass Alpha particle nuclear bombardment Beta particle strong nuclear force Gamma ray plasma plasma Nuclear chain reaction dosimeter

8. Atom Builder Activity http://www.pbs.org/wgbh/aso/tryit/atom/ http://www.pbs.org/wgbh/aso/tryit/atom/ For each addition to the atom (Up to Stable Carbon) record the following: For each addition to the atom (Up to Stable Carbon) record the following: ElementProtonsNeutronsElectronsRadioacti ve? Ionized?Stable?

9. Bohr Models of Atoms – Parts (1 of 3) Nucleus 1 amu 0Neutron Orbiting nucleus 1/1837 amu Electron Nucleus 1 amu +1Proton LocationMassChargePart

10. Determining the Part (2 of 3) = atomic mass (larger # w/ decimal, round) – atomic # Neutrons = atomic number (smaller whole #) from periodic table (assumes 0 charge, or neutral) Electrons = atomic number (smaller whole #) from periodic table Protons How to Determine Part

11. Drawing Bohr Models (3 of 3) Determine number of protons, electrons & neutrons in atom. Draw protons (+) & neutrons (0) in nucleus. Draw electrons in circles around nucleus: - 2 maximum on 1 st level. - 8 maximum on 2 nd level. - 18 maximum on 3 rd level. Asmt: Draw elements 1-18 odd (even XC)

12. Alchemist’s Dream Review (1 of 2) Q: How do you tell if it is really gold? Archimedes Principle: Determine the volume by displacement and then confirm the density. Archimedes Principle: Determine the volume by displacement and then confirm the density. Q: What did the salty vinegar do? Dark pennies have black CuO oxidation. Dark pennies have black CuO oxidation. Acid in vinegar & salt reduce the Cu +2 back to Cu 0 to reshine the penny. Acid in vinegar & salt reduce the Cu +2 back to Cu 0 to reshine the penny. Q: How did the pennies turn silver? Zinc plates on the outside of the copper. Zinc plates on the outside of the copper. Q: How did they turn to gold in the flame? Heating melts the zinc into the copper to form brass! Heating melts the zinc into the copper to form brass!

13. Alchemist’s Dream Review (2 of 2) Q: Was the removal of black CuO a chemical or physical change? A: It chemically changed from black copper salt to metallic copper. Q: Is brass a mixture or a compound? A: Brass is a mixture and an alloy. Q: Is the mixture homogeneous or heterogeneous? A: Ours varied by depth and color. So they were heterogeneous. Manufacturers produce homogeneous brass.

14. Development of Atomic Theory

15. History of the atom Not the history of atom, but the idea of the atom. Not the history of atom, but the idea of the atom. Original idea Ancient Greece (400 B.C.) Original idea Ancient Greece (400 B.C.) Democritus and Leucippus- Greek philosophers. Democritus and Leucippus- Greek philosophers.

16. John Dalton British British A small town school teacher at the age of 12. A small town school teacher at the age of 12. Introduced his atomic theory in 1803. Introduced his atomic theory in 1803.

17. Previous Findings 1. Law of Conservation of Mass Matter is neither created or destroyed in a chemical reaction. (Antoine Lavoisier) 2.Law of Definite Proportions The percentage by mass of elements in a compound is constant for any sample. Ex: H 2 O 3. Law of Multiple Proportions Compounds composed of the same two elements differ in one element by simple ratios. Ex: CO vs CO2; H2O vs H2O2

18. Law of Definite Proportions Each compound has a specific ratio of elements. It is a ratio by mass. Water has a mass of 18 grams hydrogen 2 atoms x 1.0 grams oxygen 1 atom x 16 grams The ratio is always 8 grams of oxygen for each gram of hydrogen (2 g H to 16 g O or 1 g H to 8 g O).

19. Law of Multiple Proportions Two elements or more elements may form more than one compound if they have different whole number ratio of each element. Two elements or more elements may form more than one compound if they have different whole number ratio of each element. Example: waterH 2 O Example: waterH 2 O hydrogen peroxideH 2 O 2

20. Daltons Atomic Theory 1. All matter is composed of tiny indivisible particles called atoms 2. All atoms of the same element are identical 3. Different elements have different types of atoms 4. Compounds are formed from simple combinations of atoms of different elements. 5. In a chemical reaction atoms are simply rearranged. *Activity: Ball & Stick Reactions

21. Picture Dalton’s Atomic Theory

22. Updates to Dalton’s Theory 1a. Atoms are divisible into protons, neutrons & electrons (& even smaller!). 1b. In nuclear decay they actually fall apart! 2. All atoms of a single element have the same number of protons, but not neutrons. (isotopes) 4. Compounds may be very complex!

23. Dalton’s Atomic Theory Quiz 1. W hat year was his theory published? 2. W hich previous finding defined compounds as having consistent percent compositions? 3. H ow did Dalton describe chemical reactions? 4. H ow can atoms of the same element be different?

24. Cathode Rays Tape Lab – Static electricity attractions & repulsions. Where do the charges originate? Tape Lab – Static electricity attractions & repulsions. Where do the charges originate? An evacuated glass tube when placed in an electric field An evacuated glass tube when placed in an electric field Crooke’s observed a glowing inside. Crooke’s observed a glowing inside. Thomson repeated Crooke’s experiment and did additional experiments. Thomson repeated Crooke’s experiment and did additional experiments. (-)(+)

25. Thomson’s Experiment #1 Setup: A cross was placed in the path of the glowing beam. (D?) Setup: A cross was placed in the path of the glowing beam. (D?) Observation: A shadow appeared on the anode (+) side. (D?) Observation: A shadow appeared on the anode (+) side. (D?) Interpretation: The rays come from the cathode (-) side. Interpretation: The rays come from the cathode (-) side. Cathode (-) Anode (+)

26. Thomson’s Experiment Voltage source +- Vacuum tube Metal Disks

27. Thomson’s Experiment Voltage source +-

28. Thomson’s Experiment Voltage source +-

29. Thomson’s Experiment Voltage source +-

30. n Passing an electric current makes a beam appear to move from the negative to the positive end Thomson’s Experiment Voltage source +-

31. n Passing an electric current makes a beam appear to move from the negative to the positive end Thomson’s Experiment Voltage source +-

32. n Passing an electric current makes a beam appear to move from the negative to the positive end Thomson’s Experiment Voltage source +-

33. n Passing an electric current makes a beam appear to move from the negative to the positive end Thomson’s Experiment Voltage source +-

34. Thomson’s Experiment #2 Setup: The cathode ray tube was placed in an electric field: (-) electrode on top, (+) electrode on bottom. (DPath?) Setup: The cathode ray tube was placed in an electric field: (-) electrode on top, (+) electrode on bottom. (DPath?) Observation: The cathode rays were attracted towards the (+) electrode. (D?) Observation: The cathode rays were attracted towards the (+) electrode. (D?) Interpretation: Cathode rays must be negative (-). Interpretation: Cathode rays must be negative (-).

36. Thomson’s Experiment #3 Setup: Cathode rays were placed in a magnetic field. Setup: Cathode rays were placed in a magnetic field. Observation: Cathode rays are bent perpendicular to the magnetic field. Observation: Cathode rays are bent perpendicular to the magnetic field. Interpretation: Cathode rays are not a form of light. Interpretation: Cathode rays are not a form of light.

37. Thomson’s Experiment #4 Setup: A glass wheel was placed on a level track inside the cathode ray tube. Setup: A glass wheel was placed on a level track inside the cathode ray tube. Observation: Cathode rays can rotate the glass wheel. Observation: Cathode rays can rotate the glass wheel. Interpretation: Cathode rays are particles with mass. Interpretation: Cathode rays are particles with mass.

38. Thomson Experiment #5 Setup: Thomson made cathode ray tubes with a variety of different gases & metal electrodes in the tube. Setup: Thomson made cathode ray tubes with a variety of different gases & metal electrodes in the tube. Observation: Every tube produced the same cathode rays. Observation: Every tube produced the same cathode rays. Interpretation: Cathode rays are fundamental to matter. He called cathode rays “electrons!” Discovered in 1897. Interpretation: Cathode rays are fundamental to matter. He called cathode rays “electrons!” Discovered in 1897.

39. Thomson’s Plum Pudding Model Thomson concluded that all atoms must have negative charges and positive charges to balance them. Thomson concluded that all atoms must have negative charges and positive charges to balance them. Thomson assumed that (+) & (-) charges would be evenly distributed. Thomson assumed that (+) & (-) charges would be evenly distributed.

40. Thomson’s Atomic Model Thomson believed that the electrons were like plums embedded in a positively charged “pudding,” thus it was called the “plum pudding” model.

41. Uses of cathode rays 1. A cathode ray tube (CRT) is widely used in research laboratories to convert any signal (electrical, sound, etc) into visual signals. These are called CRT or oscilloscopes. 1. A cathode ray tube (CRT) is widely used in research laboratories to convert any signal (electrical, sound, etc) into visual signals. These are called CRT or oscilloscopes. 2. CRT is the basic component in all television and computer screens. The signals are sent to the vertical and horizontal deflecting plates, which produce a pattern on the fluorescent screen. 2. CRT is the basic component in all television and computer screens. The signals are sent to the vertical and horizontal deflecting plates, which produce a pattern on the fluorescent screen. High energy cathode rays when stopped suddenly produce X-rays. The X-rays have many medical and research applications. High energy cathode rays when stopped suddenly produce X-rays. The X-rays have many medical and research applications.

45. Thomson’s Atomic Theory Quiz 1. How did Thomson know that the rays came from the cathode? 2. What did Thomson conclude from cathode rays being bent by a magnet? 3. How did Thomson know cathode rays were fundamental to matter? 4. In Thomson’s model of the atom where is the positive charge?

46. Millikan’s Oil Drop Experiment the charge of an electron with this oil-drop experiment. –1.6 x 10 -19 coulomb the charge of an electron with this oil-drop experiment. –1.6 x 10 -19 coulomb Thomson and Millikan calculated the mass of the electron to be 9.1 x 10 -28 g. This is 1/1837 the mass of a Hydrogen atom. Thomson and Millikan calculated the mass of the electron to be 9.1 x 10 -28 g. This is 1/1837 the mass of a Hydrogen atom.

47. Becquerel/Curries Becquerel - Radioactivity Curie – Discovered radioactive elements of radium and polonium Curie – Discovered radioactive elements of radium and polonium

48. Radioactivity 1. Alpha particle – is two protons and two neutrons bound together and is emitted from the nucleus, 2+ charge, 4.0 grams, least dangerous. 2. Beta particle – an electron emitted from the nucleus 1- charge 3. Gamma rays are high energy electromagnetic waves emitted from the nucleus, most dangerous.

49. Radioactivity Alpha – large Alpha – large Relatively slow Beta – much smaller Beta – much smaller Relative fast Gamma – no mass Gamma – no mass Pure energy Travels at the Speed of light

50. Ernest Rutherford New Zealander New Zealander Discoverer of alpha, beta & gamma radiation. Discoverer of alpha, beta & gamma radiation. Discovered nucleus of atom in 1912. Discovered nucleus of atom in 1912. Laserdisc demo – Side 2, Chapter 20 Laserdisc demo – Side 2, Chapter 20

51. Rutherford’s Experimental Design Uranium alpha emitter. Uranium alpha emitter. Slits to focus radiation Slits to focus radiation Gold foil target. Gold foil target. Scintillation screen of zinc sulfide to flash when hit. Scintillation screen of zinc sulfide to flash when hit.

52. Rutherford’s Prediction Positive alpha particles would go straight through or have minor deflections due to the electrons embedded in a sea of positively charged matter.

53. Rutherford’s Observations

54. Interpreting the Results Most positive alpha particles went straight through or were slightly deflected. Most positive alpha particles went straight through or were slightly deflected. Therefore the atom is mostly empty space. Therefore the atom is mostly empty space. A few positive alpha particles bounced back radically! A few positive alpha particles bounced back radically! Thus the atom must have a large concentration of positive charge! Thus the atom must have a large concentration of positive charge!

55. Rutherford’s Atomic Model

56. Development of the Bohr Model In 1913 Danish physicist Neils Bohr proposed a new model of the atom. In 1913 Danish physicist Neils Bohr proposed a new model of the atom. Bohr’s Model explained the emission and absorption patterns of light discovered by Bunsen in flames & lamps. Bohr’s Model explained the emission and absorption patterns of light discovered by Bunsen in flames & lamps.

57. Emission Lamps

58. Emission Spectra Each element emits a unique set of bright line wavelengths.

59. Emission Spectra of All the Elements http://chemistry.beloit.edu/bluelight/movi epages/em_el.htm http://chemistry.beloit.edu/bluelight/movi epages/em_el.htm http://chemistry.beloit.edu/bluelight/movi epages/em_el.htm http://chemistry.beloit.edu/bluelight/movi epages/em_el.htm http://jersey.uoregon.edu/vlab/elements/E lements.html http://jersey.uoregon.edu/vlab/elements/E lements.html http://jersey.uoregon.edu/vlab/elements/E lements.html http://jersey.uoregon.edu/vlab/elements/E lements.html http://www.webelements.com/ http://www.webelements.com/ http://www.webelements.com/

61. 4 Principles of the Bohr Model 1)Electrons assume only certain orbits around the nucleus. These orbits are stable and called "stationary" orbits. 2)Each orbit has an energy associated with it. The lowest energy levels are close to the nucleus. The farther from the nucleus corresponds to higher energy levels. Electrons tend to occupy the lowest energy levels available. 3)Light is emitted when an electron jumps from a higher orbit to a lower orbit. Light is absorbed when it jumps from a lower to higher orbit. 4)The quantity of energy and wavelength of light emitted or absorbed is given by the difference between the two orbit energies. (Quantum Leaps!)

62. With these conditions Bohr was able to explain the stability of atoms as well as the emission spectrum of hydrogen. With these conditions Bohr was able to explain the stability of atoms as well as the emission spectrum of hydrogen. Line spectra correspond to quantum leaps between levels of specific energies. Line spectra correspond to quantum leaps between levels of specific energies. Violet light corresponds to high energy quantum leaps while red light corresponds to low energy. ROYGBIV Violet light corresponds to high energy quantum leaps while red light corresponds to low energy. ROYGBIV

63. Excited State Ground State Semi-Excited State Green light emitted Red light emitted

64. Excited vs Ground States Light is absorbed when electrons jump up to higher “excited” energy levels. Light is absorbed when electrons jump up to higher “excited” energy levels. Light is emitted when electrons jump back down to their lowest energy “ground” state energy levels. Light is emitted when electrons jump back down to their lowest energy “ground” state energy levels. Animated Absorption & Emission Animated Absorption & Emission Animated Absorption & Emission Animated Absorption & Emission Fluorescent lights are constantly exciting gas atoms to emit light by passing a stream of electrons through the interior gas. Fluorescent lights are constantly exciting gas atoms to emit light by passing a stream of electrons through the interior gas.

65. The Sun’s Spectra Many elements can be identified by their unique lines. Helium was 1st discovered in the Sun’s (Helios) spectrum

66. Emission vs Absorption

68. Colors Lab A. Flame Tests NO DOUBLE DIPPING! Asthmatics may be excused Test 10 known compounds & 3 unlabeled to identify. Make data table: # Salt Formula Salt Appearance Flame Color & Effects

69. Colors Lab B. Spectral Emissions Lamp # # of Lines Colors Line Pattern ID Element Evidence

70. Comparing Atomic Models DaltonThomsonRutherfordBohr Picture of Atomic Model Evidence

71. Molecular Weight & Molar Mass Definitions: Molecular weight – the sum of all the atomic masses of all the atoms composing the molecule in terms of amu. Molar mass – the mass of a mole of a substance in terms of grams. Mole – the gram equivalent of molecular weight.

72. Molecular Weight vs Molar Mass Water – H 2 0 2 x H atoms 2 x 1.00794 = 2.01588 1 x O atom 1 x 15.999 Sum = 2.01588 + 15.999 = 18.016 amu Water – H 2 O Molar mass = gram equivalent of the molecular weight = 18.016 g

73. Percent Composition Percent Composition – the percent by mass of each element in a compound. Percent Composition – the percent by mass of each element in a compound.

74. Percent Composition of Water Water – H 2 0 2 x H atoms 2 x 1.00794 = 2.01588 1 x O atom 1 x 15.999 Sum = 2.01588 + 15.999 = 18.016 amu or g % = (part / whole)x100 % H = ? = (2.01588/18.016)100 = 11.189% %O = ? = (15.999/18.016)100 = 88.804%

75. Mole Proportions 44.0 g27.0 g4.0 gconstant # = ? 44,000,000 amu 27,000,000 amu 4,000,000 amu 1,000,000 44,000amu27,000amu4000 amu1000 440 amu270 amu40 amu10 44.0 amu27.0 amu4.0 amu1 CO 2 AlHe#

76. Moles! A mole has 3 characteristics 1. A mole is the molecular weight of a substance in grams. This is called the molar mass. This is called the molar mass. 2. A mole of any substance will have the same number of particles (atoms or molecules). A mole always has 6.02x10 23 particles for any substance. A mole always has 6.02x10 23 particles for any substance. 6.02x10 23 is called Avogadro’s Number. 6.02x10 23 is called Avogadro’s Number. 3. A mole of any gas at standard temperature and pressure has the same volume. Molar volume is 22.4L for any gas. Molar volume is 22.4L for any gas.

77. Particles (atoms or Molecules) Mole Chart (1) MolesMass (g) X ÷ ÷ x MW MM A# 6.02x10 23 MM = Molar mass in grams MW = molecular weight in grams

78. Atomic & Nuclear Chemistry

79. Geiger Counter Demos Sample Counts per Minute Reason Humans NaCl vs KCl Smoke Detector Old Fashioned Lantern Mantle Old Glow in the Dark Clock Uranium Ore

80. Radioactivity (PS1 Ch26, ) Blocked by 1ft of concrete or few inches of lead Sheet metal Blocked by paper Penetration High energy photon 1 electron 2 protons, 2 neutrons Composition 0 (movie) (movie) +2Charge 0 amu 1/1837 amu 4 amu Mass    Symbol GammaBetaAlpha Types of Radiation

81. Alpha Emission 263 Sg 106 4 He 2 + 259 Rf 104

82. http://www.remm.nlm.gov/alpha_a nimation.htm http://www.remm.nlm.gov/alpha_a nimation.htm The unstable nucleus simultaneously ejects two neutrons and two protons, which correspond to a helium nucleus. The unstable nucleus simultaneously ejects two neutrons and two protons, which correspond to a helium nucleus. The emission of gamma photons is a secondary reaction that occurs a few thousandths of a second after the disintegration. The emission of gamma photons is a secondary reaction that occurs a few thousandths of a second after the disintegration.

83. Beta Emission 14 C 6 0 e + 14 N 7 + 

84. Gamma Radiation

85. Radioactivity Shielding Lab Essential Question: There are a variety of medical diagnostic equipment which use radioactive materials inside. What is the most efficient way for manufacturers to cut down exposure for patients & medical staff? There are a variety of medical diagnostic equipment which use radioactive materials inside. What is the most efficient way for manufacturers to cut down exposure for patients & medical staff?

86. Materials: Geiger Counter, Lead box, Uranium Ore Sample, Ruler, Stop Watch, Geiger Counter, Lead box, Uranium Ore Sample, Ruler, Stop Watch, Shielding Material Options: water, paper, plastic, cardboard, glass, ceramic tiles, aluminum foil, sheet copper water, paper, plastic, cardboard, glass, ceramic tiles, aluminum foil, sheet copper

87. Radioactivity Shielding Lab What variables can we change? Distance?Material?Thickness?

88. Distance vs Radioactivity 1 st Trial 2 nd Trial Average Background 1cm 2cm 3cm 4cm 5cm

89. Shielding Material vs Radioactivity Select 5 Materials 1 st Trial 2 nd Trial Average

90. Radioactivity Lab Directions (1 of 2) As a lab group: Part A: Investigate the effect of distance on radioactivity over at least 5 different levels. 1. Write an “if, then” hypothesis. 2. Write a reason for your hypothesis. Part B: Investigate the effect of a shielding material on radioactivity. 1. Choose your unique material to vary over at least 5 different levels. 2. Write an “If, then” hypothesis. 3. Write a reason for your hypothesis. 4. Use distances that produce as large of counts as countable.

91. Safety Guidelines: 1. Always keep sample in lead box. 2. Always face opening towards the wall. 3. Rotate counters to minimize exposure.

92. Lab Requirements Determine the background radiation Determine the background radiation Use as our baselines the highest countable radioactivity possible. Use as our baselines the highest countable radioactivity possible. At least 5 different levels for each experiment. At least 5 different levels for each experiment.

93. Controlled Variables Distance same equipment, same equipment, distance increments, distance increments, time, time, Positions & angles Positions & anglesShielding same shielding material, same shielding material, distance, distance, material additions, material additions, time time

94. How Organize your Data Table? Required Elements: Level – distance or shielding Level – distance or shielding Trial – 1 st, 2 nd, or 3 rd repetition Trial – 1 st, 2 nd, or 3 rd repetition Counts – per minute (or variation) Counts – per minute (or variation) Observations – things you notice and record verbally like sources of error. Observations – things you notice and record verbally like sources of error.

95. Finish Geiger Lab – Due Friday Pick Your Roles & Rock & Roll: Safety officer Set up experiments – Control distance? Count clicks Time experiments. Record data Calculate averages Make Excel graph Powerpoint lab report – start now. Presentation

96. Recommendations for Minimizing Radiation Exposure Based on the findings of the class, what do you recommend that manufacturers use to most efficiently and effectively protect patients and employees from unnecessary exposure to radioactive diagnostic equipment? Write your recommendation in full sentences. Mention at least 2 factors. XC How could we test to see if radioactivity reflects off of the material used. Diagram the set up.

97. Side 10 - Chapter 2 – Ancient Cultures – Archaeology – C14 Dating Side 10 – PET Scan – Positrons – ½ lives Gamma rays

98. Geiger Lab Rubric Presentation Skills Points made clearly & concisely Summarizing information clearly. Summarizing, but lacking clarity. Reading to audience, lacking eye contact or loud voices. Experimental Design All external influences controlled as well. Internal variables of experiment controlled Lacking controls on internal variables. Clear independent & dependent variable. Data & Observations Complete set of multiple (>2) trials. Complete set of 2 trials for each experiment. One complete set of trials. Data missing from report. Conclusions Accurately interprets results & applies to life. Uses experimental evidence Compares results. Revisits hypothesis

99. Isotopes Atoms of a single element have the same number of protons but may differ in neutrons. Atoms of a single element have the same number of protons but may differ in neutrons. Example 1: Carbon-12 vs Carbon-14 Example 1: Carbon-12 vs Carbon-14 Example 2: Uranium-238 vs Uranium-235 Example 2: Uranium-238 vs Uranium-235 Some isotopes are stable while others are unstable and radioactive. Some isotopes are stable while others are unstable and radioactive. The STRONG NUCLEAR FORCE acts between protons & neutrons to hold them together. However protons will repel each other with their mutual positive charge. The STRONG NUCLEAR FORCE acts between protons & neutrons to hold them together. However protons will repel each other with their mutual positive charge.

100. Carbon Isotopes Isotope Half – life Carbon – 9 0.1265 s Carbon – 10 19.2 s Carbon – 11 20.38 min Carbon – 12 Stable Carbon – 13 Stable Carbon – 14 5715 y Carbon – 15 2.449 s Carbon – 16 0.75 s How long does it take 400 g of each isotope to decay to less than 1 mg? How long does it take 400 g of each isotope to decay to less than 1 mg?

101. Beanium – Average Atomic Mass Activity 7. Find the average mass of each of the 3 beanium isotopes. Average mass of ___ beans = subtotal mass/#of beans 8. % Abundance of each type = # of beans/total beans (x100 to make a %) 10. Average beanium atomic mass = (%white x avg mass white) + (%black x avg black mass) + (%red x avg red mass) *Convert the %s back into decimals to do #10.

102. Nuclear Reactions Radioactivity results from changes in atomic nuclei. Radioactivity results from changes in atomic nuclei. Fission – splitting of a large nucleus into smaller pieces releases energy. Fission – splitting of a large nucleus into smaller pieces releases energy. Fusion – small nuclei join to make a larger nucleus and release energy. (PS1, Ch25) Fusion – small nuclei join to make a larger nucleus and release energy. (PS1, Ch25) Energy is released when a small amount of mass converts to energy as E = mc 2. Energy is released when a small amount of mass converts to energy as E = mc 2.

103. Fusion of Hydrogen Isotopes At high temperatures and pressures, 2 nuclei may collide and form a bigger nucleus. At high temperatures and pressures, 2 nuclei may collide and form a bigger nucleus. This example produces helium and a stray neutron. This example produces helium and a stray neutron. Stars are fueled by the energy released by fusion which also builds atoms of increasing sizes in their cores. Stars are fueled by the energy released by fusion which also builds atoms of increasing sizes in their cores.

104. Fission of Uranium A neutron splits the nucleus. The fragments include: –2 different smaller atoms, –3 more neutrons. The 3 neutrons can split more atoms. If every fission splits 3 more atoms, the reaction will multiply out of control!

105. Nuclear Chain Reaction

106. Nuclear Warheads

107. Chernobyl Nuclear Disaster

108. Nuclear Equations Alpha (  ) Decay – releases 2 protons & 2 neutrons - a helium nucleus. Alpha (  ) Decay – releases 2 protons & 2 neutrons - a helium nucleus. Beta (  ) Decay – a neutron converts to a proton and releases an electron. Beta (  ) Decay – a neutron converts to a proton and releases an electron. 4 He 2 0 e

109. Nuclear Equations Uranium 238 does alpha decay: Uranium 238 does alpha decay: –Mass numbers balance on both sides. –Atomic numbers balance on both sides Thorium 234 then does beta decay: Thorium 234 then does beta decay: 4 He 2 238 U 92 234 Th 90 +  234 Th 90  0 e 234 Pa 91 +

110. Nuclear Equations Problems 1. U–238 does alpha decay in nuclear reactors. 2. Am-241 does alpha decay in smoke alarms. 3. Tc-99 does beta decay in medical exams. 4. C–14 does beta decay in carbon dating. 5. The Curies used Ra-226 which does alpha decay. 6. Co–60 does beta decay in food irradiation. 7. Th-232 does alpha decay in camp lanterns. 8. P-35 does beta decay in DNA studies

111. Uranium Decay Series U238 alpha - HL 4.468e9y U238 alpha - HL 4.468e9y Th234 beta – HL 24.10d Th234 beta – HL 24.10d Pa234 beta – HL 6.70h Pa234 beta – HL 6.70h U234 alpha – HL 245,500y U234 alpha – HL 245,500y Th230 alpha – HL 75,380y Th230 alpha – HL 75,380y Ra226 alpha – HL1600y Ra226 alpha – HL1600y Rn222 alpha – HL 3.8325d Rn222 alpha – HL 3.8325d Po218 alpha – HL 3.10m Po218 alpha – HL 3.10m Pb214 beta – HL 26.8m Pb214 beta – HL 26.8m Bi214 beta – HL 19.9m Bi214 beta – HL 19.9m Po214 alpha – HL 164.3  s Po214 alpha – HL 164.3  s Pb210 beta – HL 22.6y Pb210 beta – HL 22.6y Bi210 beta – HL 138d Bi210 beta – HL 138d Po210 alpha – HL 4.199m Po210 alpha – HL 4.199m Pb206 Stable! Pb206 Stable!

112. Nuclear Equations Quiz 1. Write the nuclear equation for the alpha decay of Iodine 131. 2. Write the nuclear equation for the beta decay of cobalt 60.

113. ½ Lives Activity Obtain a set of “radioactive” blocks. Notice that each one has a mark on one side – either a, b or g. Obtain a set of “radioactive” blocks. Notice that each one has a mark on one side – either a, b or g. Roll the collection of blocks onto your table. Each time you roll, remove any blocks that come up ,  or . Roll the collection of blocks onto your table. Each time you roll, remove any blocks that come up ,  or . Count and record the remaining blocks. Roll the remaining blocks repeatedly 20 times and complete the chart below. Count and record the remaining blocks. Roll the remaining blocks repeatedly 20 times and complete the chart below. Enter your group data into the excel file. Enter your group data into the excel file.excel fileexcel file Make graphs of Time(minutes) Remaining Atoms for both individual & class averages. **Use “exponential” rather than “linear” trendlines. Make graphs of Time(minutes) Remaining Atoms for both individual & class averages. **Use “exponential” rather than “linear” trendlines. Roll(minutes) Remaining Atoms Class Average

114. ½ Lives Activity Questions 1. How do your lab pair results compare with the class average results? 2. Use the class average results and compute the 1 st ½ life, 2 nd ½ life, average ½ life. 3. What importance do ½ lives have to society? (dating, medical uses, wastes)

115. ½ Lives Each radio-isotope decays at a characteristic rate. Each radio-isotope decays at a characteristic rate. The decay rate is determined by the time that it takes for ½ of the radio-isotope nuclei to break down by fission. The decay rate is determined by the time that it takes for ½ of the radio-isotope nuclei to break down by fission. Each ½ life reduces the remaining number of radioactive atoms by ½. Each ½ life reduces the remaining number of radioactive atoms by ½. The number remaining approaches but never reaches zero. The number remaining approaches but never reaches zero. Example: Iodine 131 has a ½ life of 8 days. How much of 1.00 gram sample would remain after 24 days? Example: Iodine 131 has a ½ life of 8 days. How much of 1.00 gram sample would remain after 24 days?

116. Solving ½ Life Problems Masses: STARTING MASS STARTING MASS Divided in ½ the # of half lives. Divided in ½ the # of half lives. ending mass ending massTimes: Time for 1 half life (HL) Time for 1 half life (HL) Total time elapsed (T) Total time elapsed (T) T = HL*(#) T = HL*(#) HL = T/# HL = T/# # = T/HL # = T/HL # of half lives

117. ½ Life Example 1 – Iodine 131 has a ½ life of 8 days. How much of 1.00 gram sample would remain after 24 days? Times: ½ life = 8 days Total = 24 days 24days / 8days = 3 half lives Masses: Start = 1.00 g End = ?unknown If 3 half lives occur, divide start by 2 3-times 1.00 g / 2 / 2 / 2 =.125 g

118. ½ Life Example 2: A 8.8mg sample of chromium-55 is analyzed after 15 min and found to contain 1.1mg remaining. What is the ½ life of Cr55? Masses: Start = 8.8 mg End = 1.1mg Divide 4.4 by 2 until reaching 1.1. 8.8/2 = 4.4 4.4/2 = 2.2 2.2/2 = 1.1 3 – ½ lives occurred Times: Total = 15 min ½ life = ? Unknown Divide 15 min by 3 – ½ lives 15min/3 HL = 5 min/1HL 5 min = 1 – ½ life

119. ½ Life Problems 1. If you have $1 million dollars and every 2 seconds it decreases by 1/2, how long will it take until you are penniless? 2. If a sample of a fossil mammoth has 1/8 th the amount of carbon 14 as it would today, how old must the fossil be? (1/2L C14 = 5715 years. 3. If a rock contained 1.2 g of potassium 40 when it formed, how many grams remain after 4 billion years. (1/2L K40 = 1.33E9 y) Asmt: P780 #1&2, P803 #24&25

120. More ½ Life Problems 4. If a sample of radioactive isotope has a half-life of 1 year, how much of the original sample will be left at the end of the second year? The third year? The fourth year? 5. The isotope cesium-137, which has a half-life of 30 years, is a product of nuclear power plants. How long will it take for this isotope to decay to about one- sixteenth its original amount? 6. Iodine-131 has a half-life of 8 days. What fraction of the original sample would remain at the end of 32 days? 7. The half-life of chromium-51 is 28 days. If the sample contained 510 grams, how much chromium would remain after 56 days? How much would remain after 1 year?

121. ½ Lives Quiz 1. A sample of a radioactive isotope with an original mass of 8.00g is observed for 30 days. After that time, 0.25g of the isotope remains. What is its half-life? 2. The starting mass of a radioactive isotope is 20.0g. The half-life period of this isotope is 2 days. The sample is observed for 14 days. What PERCENTAGE of the original amount remains after 14 days?

122. Health Physics Society http://hps.org/publicinformation/ate/q754.html http://hps.org/publicinformation/ate/q754.html http://hps.org/publicinformation/ate/q754.html Q:What are some health effects of the element uranium? Q:What are some health effects of the element uranium? A:The toxicity of uranium has been under study for over 50 years, including life-span studies in small animals. Depleted uranium and natural uranium both consist primarily of the uranium isotope 238U. They are only very weakly radioactive and are not hazardous radioactive toxicants, but uranium is a weak chemical poison that can seriously damage the kidneys at high blood concentrations. Virtually all of the observed or expected effects are from nephrotoxicity associated with deposition in the kidney tubules and glomeruli damage at high blood concentrations of uranium. The ionizing radiation doses from depleted and natural uranium are very small compared to potential toxic effects from uranium ions in the body (primarily damage to kidney tubules). A:The toxicity of uranium has been under study for over 50 years, including life-span studies in small animals. Depleted uranium and natural uranium both consist primarily of the uranium isotope 238U. They are only very weakly radioactive and are not hazardous radioactive toxicants, but uranium is a weak chemical poison that can seriously damage the kidneys at high blood concentrations. Virtually all of the observed or expected effects are from nephrotoxicity associated with deposition in the kidney tubules and glomeruli damage at high blood concentrations of uranium. The ionizing radiation doses from depleted and natural uranium are very small compared to potential toxic effects from uranium ions in the body (primarily damage to kidney tubules).

123. Modern Atomic Theory Quantum Mechanical Model (Electron Cloud Model)

124. Electrons & Standing Waves 1. Electrons don’t move in straight lines; they move as waves. 2. Electron microscopes allow us to see flies eyes since electron wavelengths are shorter than visible light waves. 3. Electrons orbiting a positive nucleus settle into low energy standing waves 4. Demo – Standing waves

125. Orbitals 1. Electron wave orbits are too complicated to track. 2. Chemists describe their probable location as clouds. 3. Orbitals are defined as the space they occupy 90% of the time. 4. Demo: Electrons occupy orbitals like fan blades

126. Orbital Demos 1. Electrons move so fast they occupy space like fan blades! 2. The most stable patterns for electron wave motions are standing waves! 3. *Electrons move fastest passing the nucleus and spend little time there. http://galileoandeinstein.physics.virginia.edu /more_stuff/flashlets/Slingshot.htm http://galileoandeinstein.physics.virginia.edu /more_stuff/flashlets/Slingshot.htm 1. Orbital Diagrams 2. Video – CheMedia Side 2, Chapter 23

141. F orbitals Start at the fourth energy level Start at the fourth energy level Have seven different shapes Have seven different shapes 2 electrons per shape for a total of 14 electrons. 2 electrons per shape for a total of 14 electrons.

142. F orbitals

143. Electron Orbitals Level 4 7 8 Lobed F Level 3 5CloverleafD Level 2 3Dumb-bellP Level 1 1SphericalS 1 st Occur SetShapeType

144. Electron Configurations Orbitals can hold 2 electrons each. Orbitals can hold 2 electrons each. Lowest energy orbitals fill first. Lowest energy orbitals fill first. Electrons repel and occupy separate orbitals on the same energy level if possible. Electrons repel and occupy separate orbitals on the same energy level if possible. Orbital Packing Key: Orbital Packing Key: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 ……. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 ……. Animated Electron Configurations Animated Electron Configurations

145. Orbital filling table

147. Electron Configurations vs Pictures 1 H + - 1s 1

148. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 - +

149. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - +

150. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + +

151. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + + 5 B 1s 2 2s 2 2p 1 - +

152. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + 5 B 1s 2 2s 2 2p 1 - + 6 C 1s 2 2s 2 2p 2 - + +

153. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + + 5 B 1s 2 2s 2 2p 1 - + 6 C 1s 2 2s 2 2p 2 - + + 7N 1s 2 2s 2 2p 3 -

154. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + + 5 B 1s 2 2s 2 2p 1 - + 6 C 1s 2 2s 2 2p 2 - + + 7N 1s 2 2s 2 2p 3 - + 8O 1s 2 2s 2 2p 4 -

155. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + + 5 B 1s 2 2s 2 2p 1 - + 6 C 1s 2 2s 2 2p 2 - + + 7N 1s 2 2s 2 2p 3 - + 8O 1s 2 2s 2 2p 4 - 9F 1s 2 2s 2 2p 5 -

156. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + + 5 B 1s 2 2s 2 2p 1 - + 6 C 1s 2 2s 2 2p 2 - + + 7N 1s 2 2s 2 2p 3 - + 8O 1s 2 2s 2 2p 4 - 9F 1s 2 2s 2 2p 5 - 10Ne 1s 2 2s 2 2p 6 + -

157. Electron Configurations vs Pictures 1 H + - 1s 1 2 He1s 2 + - 3 Li 1s 2 2s 1 - 4 Be 1s 2 2s 2 - + + 5 B 1s 2 2s 2 2p 1 - + 6 C 1s 2 2s 2 2p 2 - + + 7N 1s 2 2s 2 2p 3 - + 8O 1s 2 2s 2 2p 4 - 9F 1s 2 2s 2 2p 5 - 10Ne 1s 2 2s 2 2p 6 + - - 11Na 1s 2 2s 2 2p 6 3s 1

158. - - - - - - - - - - Electron Configurations vs Pictures + + + + + + + + + -

159. - - - - - - - - - - + + + + + + + + + -

160. - - - - - - - - - - + + + + + + + + + -

161. Examples: 1. Write the electron configuration & draw an atom of fluorine. Asmt: Write electron configurations of elements 1,5,9,13,17,21,25,29.

162. Electron Configurations Quiz 1 1. Write the full electron configuration & draw the atom for nitrogen, N – atomic number 7, atomic mass 14.01. 2. Write the full & Noble Gas electron configurations for nickel, Ni – atomic number 28. 3. Identify the element with the Noble Gas electron configuration of [Ar]4s 2 3d 6. Explain how you know.

163. Photoelectric Effect & Solar Energy http://www.walter- fendt.de/ph14e/photoeffect.htm http://www.walter- fendt.de/ph14e/photoeffect.htm http://www.walter- fendt.de/ph14e/photoeffect.htm http://www.walter- fendt.de/ph14e/photoeffect.htm http://phet.colorado.edu/new/simulations/ sims.php?sim=Photoelectric_Effect http://phet.colorado.edu/new/simulations/ sims.php?sim=Photoelectric_Effect http://phet.colorado.edu/new/simulations/ sims.php?sim=Photoelectric_Effect http://phet.colorado.edu/new/simulations/ sims.php?sim=Photoelectric_Effect http://www1.eere.energy.gov/solar/photo electric_effect.html http://www1.eere.energy.gov/solar/photo electric_effect.html http://www1.eere.energy.gov/solar/photo electric_effect.html http://www1.eere.energy.gov/solar/photo electric_effect.html http://www.electronsolarenergy.com/reso urces.htm http://www.electronsolarenergy.com/reso urces.htm http://www.electronsolarenergy.com/reso urces.htm http://www.electronsolarenergy.com/reso urces.htm

164. Tuesday 11/27/07 Prep: 1. See Neil about Periodic Table Activities 2. Determine Periodic Table book assignment Class: Periods 1 & 3 DMA: What element corresponds to the configuration [Kr]5s 2 4d 10 5p 5 ? 1. Take & correct quiz 2. Periodic Table Activity Asmt: Page 163 #1-4, page 173 #1,3, page 185 #2 Plan: Meet with POD Periods 4-6 Library Utopia Project Afterschool: 1. Grade Poster Projects 2. Contact National Boards about appeal of Active Inquiry 3. Go to Wells Fargo 1.Deposit checks, get new registers! 2.Provide mortgage documents

165. Orbital Animations Chemedia Laserdisc Demo – Side 2, Chapter 23 Chemedia Laserdisc Demo – Side 2, Chapter 23 http://www.colby.edu/chemistry/OChem/ DEMOS/Orbitals.html http://www.colby.edu/chemistry/OChem/ DEMOS/Orbitals.html

166. Electron Configurations Quiz 2 1. Write the electron configuration & draw an atom of oxygen. 2. Write the complete and Noble Gas configurations for arsenic, As. 3. Identify the element that approximately matches [Xe]6s 2 5d 10 4f 14 6p 2 & explain how you know.

167. Periodic Table Activity

168. Thursday 11/29/07 Prep: 1. Grade fireworks posters. Class:P1-3 DMA: What principle determines which elements are in the same vertical column? Due: Page 163,173,185, Fill in blanks? 1. Fill in blanks Periodic Table, 1 part at a time 2. Notes on Development of Periodic Table Asmt: Shade sections of 9 overlapping sections of Periodic Table (pages 164-7) Plan: 1. Finalize POD meeting plans & Sliding Scenario pieces. 2. Grade Fireworks posters. P4-6 DMA: Electron Configurations Quiz 2 1. Grade Quiz 2. Periodic Table Card Puzzle Asmt: Asmt: Shade sections of 9 overlapping sections of Periodic Table (pages 164-7) After School: 1. Grade fireworks posters 2. Thursday chores at home plus piano practicing. 3. Left overs, chips to Men’s group.

169. Development of the Periodic Table (1 of 2) Periodic Law – When elements are arranged in increasing atomic number, their chemical & physical properties show a periodic pattern. Periodic Law – When elements are arranged in increasing atomic number, their chemical & physical properties show a periodic pattern. Dobereiner grouped the elements into triads with similar chemical properties. Dobereiner grouped the elements into triads with similar chemical properties. Newlands arranged the elements by increasing atomic mass and observed the Law of Octaves where elements of similar properties occurred every 8 th element. Newlands arranged the elements by increasing atomic mass and observed the Law of Octaves where elements of similar properties occurred every 8 th element.

170. Development of the Periodic Table (2 of 2) Mendeleev arranged the elements by increasing mass & similar properties in 1872. Mendeleev arranged the elements by increasing mass & similar properties in 1872. Mendeleev suggested that atomic masses that were out of line with the similar properties needed to be remeasured. Mendeleev suggested that atomic masses that were out of line with the similar properties needed to be remeasured. Mendeleev accurately predicted the existence and properties of elements yet to be discovered. Mendeleev accurately predicted the existence and properties of elements yet to be discovered. Moseley discovered a pattern in the spectral lines of elements which corresponded to the atomic number and number of protons. Moseley discovered a pattern in the spectral lines of elements which corresponded to the atomic number and number of protons.

171. Periodic Table Patterns http://www.sciencebyjones.com/periodic_t able1.htm http://www.sciencebyjones.com/periodic_t able1.htm http://www.sciencebyjones.com/periodic_t able1.htm http://www.sciencebyjones.com/periodic_t able1.htm http://environmentalchemistry.com/yogi/p eriodic/#Chemical%20elements%20sorted %20by http://environmentalchemistry.com/yogi/p eriodic/#Chemical%20elements%20sorted %20by http://environmentalchemistry.com/yogi/p eriodic/#Chemical%20elements%20sorted %20by http://environmentalchemistry.com/yogi/p eriodic/#Chemical%20elements%20sorted %20by Can use the one above to find the patterns & then explain them. Can use the one above to find the patterns & then explain them.

172. Observing Element Samples 1. Use your blank periodic table with trends of electron configurations. 2. Observe 2 samples from each of the 9 sets around the room. 3. For each sample, record the symbol in the correct box plus 2 words to describe the appearance of the sample.

173. Monday 12/2/07 Periodic trends – atomic radius, ionization energy, electronegativity Periodic trends – atomic radius, ionization energy, electronegativity Analyze data & graphs, Explain trends Analyze data & graphs, Explain trends

174. Patterns of Electron Configurations Vertical Patterns Horizontal Patterns Same number and type of valence electrons. Same kernel across Energy level rises for each row. The kernel is the previous noble gas Highest energy level is the same across a row.

175. Patterns of Electron Configurations Vertical Patterns Vertical Patterns Same number and type of valence electrons. Same number and type of valence electrons. Energy level rises for each row. Energy level rises for each row. Horizontal Patterns Horizontal Patterns Same kernel across Same kernel across The kernel is the previous noble gas The kernel is the previous noble gas Highest energy level is the same across a row. Highest energy level is the same across a row.

176. Periodic Patterns [x] [:x:] : : : :.. O : : : : Ne : :.. X H. X. Be : X : X :. Al. : C :.... X : :... N... : X : :. F : X : : : : : :. X : He : [:x:] : : : : [x] +4 -4 +1+2 +3 -3 -2 s1s1 s2s2 s2p1s2p1 s2p2s2p2 s2p3s2p3 s2p4s2p4 s2p5s2p5 s2p6s2p6 Ion formation: Loss (oxidation) or gain (reduction) of electrons

177. Periodic Trends Trends in atomic radius, ionization energy, & electronegativity are determined by: Trends in atomic radius, ionization energy, & electronegativity are determined by: The number of energy levels present. The number of energy levels present. The attraction between the positive nucleus and the outer shell electrons. The attraction between the positive nucleus and the outer shell electrons. Interfering “shielding” by electrons on inner shells. Interfering “shielding” by electrons on inner shells. How close an atom is to completing the stable octet of outer “valence” electrons. How close an atom is to completing the stable octet of outer “valence” electrons.

178. Atomic Radius (1 of 3) Alkali metals are the largest atoms. Alkali metals are the largest atoms. Noble gases are the smallest atoms. Noble gases are the smallest atoms.

179. Atomic Radius (2 of 3) Atomic radius trends: 1) Atomic radius increases down a group or column. 2) Atomic radius decreases across a period or row.

180. Atomic Radius (3 of 3) How do we explain the trends? 1. Atomic radius increases down a group: Each row adds an energy level.Each row adds an energy level. Interior electrons interfere with attraction of valence electrons toward the nucleus “shielding effect”Interior electrons interfere with attraction of valence electrons toward the nucleus “shielding effect” 2. Atomic radius decreases across a row even while the atomic number increases: While in the same energy level, the nucleus becomes more positive & attractive.While in the same energy level, the nucleus becomes more positive & attractive.

181. Ionization – Removal of electrons produces + charges & shrinks radius. Ionization – Removal of electrons produces + charges & shrinks radius. http://hogan.chem.lsu.edu/matter/chap26/anim ate2/an26_017.mov http://hogan.chem.lsu.edu/matter/chap26/anim ate2/an26_017.mov http://hogan.chem.lsu.edu/matter/chap26/anim ate2/an26_017.mov http://hogan.chem.lsu.edu/matter/chap26/anim ate2/an26_017.mov Animated Ionizations Change Radii Across periodic table. Animated Ionizations Change Radii Across periodic table. http://www.chem.iastate.edu/group/Greenbowe /sections/projectfolder/flashfiles/matters/periodi cTbl2.html http://www.chem.iastate.edu/group/Greenbowe /sections/projectfolder/flashfiles/matters/periodi cTbl2.html

182. Ionization Energy (1 of 4) Ionization energy is the energy required to remove a negative electron and leave an atom with a positive charge – as an ion. Ionization energy is the energy required to remove a negative electron and leave an atom with a positive charge – as an ion. Occurs in solar cells, geiger counters & smoke detectors with Amerecium 241 Occurs in solar cells, geiger counters & smoke detectors with Amerecium 241

183. Ionization Energy (2 of 4) Alkali metals lose their electrons most easily. Alkali metals lose their electrons most easily. Noble gases hold their electrons most tightly. Noble gases hold their electrons most tightly.

184. Ionization Energy (3 of 4) Removing an electron becomes more difficult across a row. Removing an electron becomes more difficult across a row. Removing electrons becomes easier down a column. Removing electrons becomes easier down a column.

185. Ionization Energy (4 of 4) Removing electrons is more difficult across a row as the nuclear attractions become stronger. Removing electrons is more difficult across a row as the nuclear attractions become stronger. Removing electrons is easier down a column as each additional energy level increases the distance from the nucleus and weakens the nuclear attraction. Removing electrons is easier down a column as each additional energy level increases the distance from the nucleus and weakens the nuclear attraction. Repulsive shielding by interior electrons also decreases the attraction for each added level. Repulsive shielding by interior electrons also decreases the attraction for each added level.

186. Electronegativity (1 of 3) Electro- negativity is the ability of an atom to attract electrons that are shared in a covalent bond. Electro- negativity is the ability of an atom to attract electrons that are shared in a covalent bond. Equal Sharing Unequal Sharing H2H2 HCl 2.1 3.5 Electrons hogged by Cl

187. Electronegativity (2 of 3) What are the trends in electronegativity? What are the trends in electronegativity?

188. Electronegativity (3 of 3) Electronegativity increases up & to the right. Electronegativity increases up & to the right. This trend corresponds to stronger attractions to the nucleus. This trend corresponds to stronger attractions to the nucleus. Less shielding effect strengthens attractions to the nucleus in upper rows. Less shielding effect strengthens attractions to the nucleus in upper rows.

189. Periodic Patterns Quiz 1. Atomic Radius Question – a) What is the size surprise? b) Why does it occur? 2. Ionization Energy – Why are the lowest ionization energies in the bottom left? 3. Electronegativity – Arrange each set of atoms in order from least to greatest electronegativity: a) Mg, Ba, Sr; b) Cl, F, I; c) Fe, K, Br

190. Periodic Patterns of Reactivity Choose an element from the periodic table. Choose an element from the periodic table. Predict how you think it will react with air, water, acids or bases. Predict how you think it will react with air, water, acids or bases. Observe the laserdisc video. Observe the laserdisc video. Record the reactivity on a 1R-10R scale. Record the reactivity on a 1R-10R scale. Examine no more than 3 per group. Examine no more than 3 per group. Identify patterns of reactivity. Identify patterns of reactivity.

191. Periodic Patterns of Reactivity

192. Comparing Periodic Groups Noble Gases Halogens Oxygen Nitrogen Carbon Boron Transition Alkaline Earth Na – table salt K - gatorade Electrolyze salts Soft metals, Explode in H2O +1 S1S1S1S1Alkali Uses of 2 elements of Group Sources of 2 – How obtained Properties Common Ionic ChargesCommon Valence Electrons Group

193. Comparing Periodic Groups GroupValencesIons, # of Bonds Properties Sources of 2 – How obtained Uses of 2 elements min AlkaliS1 +1, ionic Soft metals, explosive Electrolyze salts Na – table salt K – gatorade Alkaline Earth S2 +2, ionic Soft, highly reactive Electrolyze salts Ca – bones, Mg – flash bulbs Transition S2d1 – s2d10 Various charges +2,+3, +4 Hard metals, w/ varying resistance Mined & extracted from ores Iron in steel, Gold jewelry BoronS2p1 +3, (or 3 bonds) Nonmetals & metals Extracted from bauxite ore Al - cans CarbonS2p2 + or – 4, 4 bonds Nonmetals to metals Common in life, rocks & ores C – pencils, Si – chips, Pb – wts Nitrogens2p3 -3, 3 bonds Non-metals, semi-metals N from air, P from phosphates Fertilizers OxygenS2p4 -2, 2 bonds Non-metals to metals O from air, S mined Breathing, make sulfuric acid HalogensS2p5 -1, 1 bond Reactive Nonmetals Electrolyze salts Cl – bactericide F - toothpaste Noble Gases S2p6 0, 0 bonds Unreactive gases Isolated from air He – balloons Ar – light bulbs