1 / 54

Bellringer: 2/27/2017

Bellringer: 2/27/2017. What do you know about electrons? What do you know about light? STOTD **You will need a calculator and reference table. Updates: Monday: Start Unit 3: Light Tuesday: Atomic emission, Bohr Model , JUNIORS TAKE ACT (1 ST -3 RD ) Wednesday: Atomic Emission Dry Lab

mistyd
Télécharger la présentation

Bellringer: 2/27/2017

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bellringer: 2/27/2017 • What do you know about electrons? • What do you know about light? • STOTD **You will need a calculator and reference table Updates: Monday: Start Unit 3: Light Tuesday: Atomic emission, Bohr Model, JUNIORS TAKE ACT (1ST-3RD) Wednesday: Atomic Emission Dry Lab Thursday: QUIZ, Electron Configuration Friday: Electron Configuration Monday: Periodic Table Tuesday: Review Wednesday: TEST

  2. Electrons in Atomsand The Periodic Table Chapters 4 and 5

  3. Unanswered Questions • How are the electrons placed around the nucleus? • Why are the electrons NOT pulled into the nucleus? • Opposites attract • To answer these questions, scientists needed to have a new understanding of LIGHT. • Starting with Electromagnetic Radiation: • A form of energy that moves like waves through space end

  4. Properties of Light • Visible light is a part of the Electromagnetic (EM) Spectrum • Energy that moves like a wave • Last page of Reference Tables • Wavelength (λ) • Distance between 2 identical points • Meters • Frequency (ν) • Number of waves in 1 second • Hertz (Hz) or 1/s, which is (s-1) end

  5. Properties of Light • All EM waves travel at the Speed of Light (c) • c = 3.00 x 108 m/s • As frequency goes up: • Wavelength goes down • Energy goes up λ v E end

  6. Electromagnetic Spectrum Visible Spectrum

  7. Properties of Light • A gamma ray has a wavelength of 7.00 x 10-13 m. What is the frequency of this ray? • A ray has a wavelength of 5.50 x 10-7 m. What is the frequency of this ray? What type of EM wave is this? • A ray has a frequency of 7.65 x 10-2 Hz. What is the wavelength of this ray? What type of EM wave is this? • A satellite transmits on the EM Spectrum at a frequency of 9.4 x 109 Hz. What is the signal’s wavelength? • What type of wave is being transmitted? • A beam of visible light has a frequency of 4.5x1014 Hz. • What is the wavelength of this light? • What color is this light? end

  8. Properties of Light • Light does not always act like a wave • The Photoelectric Effect • Metal gives off electrons when light shines on it • Depends on the frequency of the light • Not the amount of light • Max Planck (1900) • Matter gains/loses energy in specific amounts known as Quanta • Quantum • The minimum amount of energy that can be gained/lost Frequency Energy Planck’s Constant (6.626 x 10-34 J·s) end

  9. Properties of Light • What is the energy of an EM wave with a frequency of 6.32 x 1026 Hz? • What is the energy of an EM wave with a frequency of 4.56 x 1015 Hz? • What is the energy of an EM wave with a frequency of 9.5 x 1030 Hz? • What energy would a beam of microwaves have if their wavelength is 5.6 x 10-2 m? (2 step problem) • A beam of visible light has a wavelength of 5.8 x 10-7 m. What is its energy and what color is it? (2 step problem) end

  10. Bellringer: 2/27/2017 • How fast does an EM Wave travel? • How are EM waves different from each other? • Describe the relationship between v, E, and λ. • STOTD **You need a calculator and reference table today Updates: Tuesday: Atomic emission, Bohr Model, JUNIORS TAKE ACT (1ST-3RD) Wednesday: Atomic Emission Dry Lab Thursday: QUIZ, Electron Configuration Friday: Electron Configuration Monday: Periodic Table Tuesday: Review Wednesday: TEST

  11. Properties of Light • Albert Einstein (1905) • Wave-Particle Duality • All matter and energy can act as both a wave and a particle • Photon • A particle of light • The energy of a photon depends on the frequency end

  12. Line-Emission • Ground State: The lowest energy state of an atom • Excited State: The highest energy state of an atom • How can we see the change between states? • You can use a spectroscope • When a narrow beam of light is shined through a prism, it is separated into a series of specific wavelengths of visible light.

  13. Emission Spectrum • Atomic Emission Spectrum • When given energy, every element gives off specific frequencies of light end

  14. Line-Emission Spectrum O2 end

  15. Atomic Theories- Bohr • Niels Bohr (1913) • Electrons are placed into Energy Levels • Circular orbits around the nucleus • Number of electrons in each orbit = 2n2 • Cannot be between energy Levels • Gain energy, electrons move up energy levels • To an Excited State • Release energy, electrons move down energy levels • To the Ground State • Bigger Move = More Energy end

  16. Atomic Theories- Bohr • If an electron drops from n=3 to n=2 what would be the approximate wavelength of the light emitted? • If an electron drops from n=4 to n=1 what type of EM radiation would be produced? What is its wavelength? end

  17. Atomic Theories- Bohr • Determine the wavelength, frequency, and type of EM wave for each of the following transitions. • n = 4  n = 1 • n = 5  n = 2 • n = 6  n = 3 end

  18. Atomic Theories- Bohr Lets draw Li-6 p = 3 n = 3 e = 3 Lets draw H-1 p = 1 n = 0 e = 1 Lets draw Na-22 p = 11 n = 11 e = 11 Lets draw He-4 p = 2 n = 2 e = 2 end

  19. HW • Draw Bohr Models for the following isotopes: • Be-10 • F-18 • Mg-24 • P-30 • Ar-40

  20. Bellringer: • How can you use the Bohr Model to predict light emission? • Using your reference table determine the wavelength of light being produced from the following transitions: • n=4→n=3 • n=6 →n=3 • STOTD **You will need a calculator and your reference table today**

  21. Atomic Emission Lab

  22. Bellringer: • List the electromagnetic waves in order from shortest wavelength to longest wavelength. • STOTD *

  23. Bellringer: • List the electromagnetic waves in order from shortest wavelength to longest wavelength. • Calculate the energy of a wave that has a wavelength of 5.50 x 10-4 m. What type of EM wave is this? • STOTD

  24. Atomic Orbitals & Quantum Numbers • From the new research scientists created the Electron Cloud Model • Nucleus with electrons orbiting in an area of high probability • Atomic Orbital • A 3-D area where you have a 95% chance of finding an electron • The Principal Quantum Number (n) • Indicates the Energy Level • 1, 2, 3, …7 • Bigger Numbers = Higher Energy • Each Energy Level has sublevels end

  25. Atomic Orbitals & Quantum Numbers • Angular Momentum Quantum Number (l) • The Shape of each sublevel • l = 0, 1, 2, …n-1 • Labeled: s, p, d, f, g, h… p l = 1 Dumbell (Peanut) 3 orbitalsin each Energy Level s l = 0 Sphere 1 orbital in each Energy Level end

  26. Atomic Orbitals & Quantum Numbers d l = 2 5 orbitals in each Energy Level 4 Daisy 1 Peanut in a Doughnut f l = 3 7 orbitals in each Energy Level g l = 4 9 orbitals in each Energy Level h l = 5 11 orbitalsin each Energy Level end

  27. Atomic Orbitals & Quantum Numbers end

  28. Electron Configuration • Electrons are arranged in a specific way according to 3 rules: • RULE 1: • Aufbau Principle • Electrons will occupy the LOWEST energy level possible • Energy Levels = 1 is the lowest • Sublevels = s < p < d < f • Sublevels “d” and “f” overlap with the next Energy Level end

  29. Electron Configuration • RULE 2: • Pauli Exclusion Principle • ONLY 2 electrons in each ORBITAL • Electrons MUST have opposite Spins end

  30. Electron Configuration • RULE 3: • Hund’s Rule • 1 electron in each orbital of a sublevel before you can double up Unpaired Electrons Paired Electrons end

  31. Bellringer: • What is electron configuration? • What is an atomic orbital? • How many electrons can one orbital hold? • What does the angular momentum quantum number tell you? • STOTD

  32. Bellringer: • What element has the following electron configuration: 1s22s22p63s23p64s23d7 • Using the electron configuration above, what is the angular momentum quantum number for the electrons furthest from the nucleus? • What is an atomic orbital? • STOTD

  33. HW Problems from last night: • Electron Configuration for: • Lithium • Nitrogen • Sodium • Chlorine • Vanadium

  34. Electron Configuration • Electron Configuration Notation • Instead of drawing all of the lines, use superscripts • Be • F • Mg • He • Ar • B end

  35. Bellringer: • Orbital Notation • Draw a line and label each Energy Level and Sublevel • Add arrows to represent electrons • C • Ne • Ca • Use your Periodic Table to determine the electron configuration for the following elements in Orbital Notation: **STOTD** end

  36. Bellringer: • What scientist created the theory of wave-particle duality? • Draw the Bohr Model for 29Si. • What is a photon? • STOTD

  37. The Periodic Table By 1860 scientists had discovered 63 elements But no good way to organize them Scientists memorized everything This was changed by Mendeleev end

  38. The Periodic Table Mendeleev’s Periodic Table: Elements with similar properties were placed in the same column The mass of the elements increased along each row end

  39. The Periodic Table Mendeleev left several blank spaces in his periodic table For elements that had not been discovered yet He correctly predicted the properties of these elements based on the elements around them end

  40. The Periodic Table The Modern Periodic Table: Based on Mendeleev’s table Similar Properties are in the Same Column Columns are called Groups Numbered 1 to 18 (from left to right) Atomic Numbersincrease going across the table Rows are called Periods Numbered 1 to 7 (from top to bottom) end

  41. The Periodic Table • This is the full Periodic Table • As you can see it is REALLY long • Way too long to fit on a page end

  42. The Periodic Table • To make everything fit on 1 page, the Lanthanides and Actinides are moved to the bottom end

  43. Electron Configuration and the P.T. Energy Levels (n) 1 2 3 3 4 4 5 5 6 7 6 4 5 end

  44. Electron Configuration and the P.T. Sublevels (l) p s d f end

  45. Electron Configuration and the P.T. • Instead of remembering the Aufbau diagram just read the Periodic Table • Add 1 electron for each element you pass • N • Si • Ti • Mg • Mo • I end

  46. The Periodic Table • Valence Electrons • Electrons in the highest energy level • Only thing involved in a chemical reaction • Give Elements their Chemical Properties • Group: 1 2 13 14 15 16 17 18 • # of 1 2 3 4 5 6 7 8 • Valence: end

  47. The Periodic Table Metals Francium (Fr) is the most reactive Conduct electricity/heat Mostly solids at room temperature High melting/boiling points Can bend without breaking Nonmetals Fluorine (F) is the most reactive nonmetal Poorly conduct heat/electricity Mostly gases at room temperature Low melting/boiling points Break when bent end

  48. The Periodic Table Metalloids Touching the stair-step line Properties between metals and nonmetals Depends on the temperature end

  49. The Periodic Table Alkali Metals EXTREMELY REACTIVE! Transition Metals Wide Range of Properties Lanthanide and Actinide Series All are radioactive end

  50. The Periodic Table Halogens Highly Reactive Noble Gases Extremely Unreactive THEY DO NOTHING! end

More Related