1. How can we describe an atom? How can atoms of the same element be both similar and different at the same time? What do we call an atom that is not neutral? How can we calculate the average mass of isotopes? How has the model of the atom evolved over time? How can we describe the modern model of the atom? How can we describe where are electrons are located within the electron cloud? How can we describe how electrons are arranged? What is electromagnetic radiation? How is light produced? - Honors Chemistry

2. AIM: How can we describe an atom? The Theory of the Atom ________________, a famous Greek teacher who lived in the 4th Century B.C., first suggested the idea of the atom. ________ __________ came up with his atomic theory based on the results of his experiments. The Atom The smallest particle of an ________________ is an atom. The atom is made up of three ________________ particles. (1)The electron was discovered in _______ by J. J. Thomson by using a cathode ray tube. The electron has a _______ charge. It’s mass is much smaller than the other 2 subatomic particles, therefore it’s mass is usually ______________. Democritus John Dalton element subatomic 1897 (−)(−) ignored

4. (2) The proton has a ______ charge, and it was discovered in _________ by E. Goldstein. (3) The neutron does not have a charge. In other words, it is ________. It was discovered in ____ by James Chadwick. The neutron has about the same _________ as the proton. * These three particles make up all the ____________________ in the Universe! * There are other particles such as neutrinos, positrons, and quarks, but are typically left for 2 nd year chemistry courses. neutral1932 mass visible matter (+) 1886

5. Nuclear Atomic Structure * The atom is made up of 2 parts/sections: (1) The ______________ --- (in the center of the atom) (2) The ____________ _________ --- (surrounds the nucleus) nucleus electron cloud (p + & n 0 ) e − cloud

6. The Nucleus * Discovered by Ernest ________________ in ________. * He shot a beam of positively charged “alpha particles”, which are ___________ nuclei, at a thin sheet of ______ _____. * 99.9% of the particles went right on through to the ______________. Some were slightly deflected. Some even ____________ ________ towards the source! This would be like shooting a cannon ball at a piece of tissue paper and having it bounce off. Rutherford1911 heliumgold foil detector bounced back

8. (1) Most of the atom is more or less _________ ___________. (2) The nucleus is very _________. (Stadium Analogy) (3) The nucleus is very ___________. (Large Mass ÷ Small Volume) (4) The nucleus is ______________ charged. empty space dense tiny positively Counting Subatomic Particles in an Atom The atomic # of an element equals the number of ____________ in the nucleus. The mass # of an element equals the sum of the _____________ and ______________ in the nucleus. In a neutral atom, the # of protons = # of ______________. To calculate the # of neutrons in the nucleus, ______________ the ___________ # from the __________ #. protons neutrons electrons subtract atomicmass

9. (1) Find the # of e -, p + and n 0 for sodium. (mass # = 23) 2) Find the # of e -, p + and n 0 for uranium. (mass # = 238) 3) What is the atomic # and mass # for the following atom? # e - = 15; # n 0 = 16 Atomic # = 11 = # e - = # p + # neutrons = 23-11 = 12 Atomic # = 92 = # e - = # p + # neutrons = 238-92 = 146 Atomic # = 15 = # e - = # p + Mass # = p + + n 0 = 15+16 =31 The element is phosphorus!

10. REMEMBER  P….E….N

11. Element NameSymbolAtomic #AMU# of Protons # of Electrons # of Neutrons K19 5 16 23 10 48 25 14

12. * AIM: How can atoms of the same element be both similar and different at the same time?- Isotopes

13. * An isotope refers to atoms that have the same # of ___________, but they have a different # of ___________. * Because of this, they have different _________ #’s (or simply, different ___________.) * Isotopes are the same element, but the atoms weigh a different amount because of the # of ______________. Examples---> (1) Carbon-12 & Carbon-13 (2) Chlorine-35 & Chlorine-37 (The # shown after the name is the mass #.) * For each example, the elements have identical ___________ #’s, (# of p + ) but different _________ #’s, (# of n 0 ). * Another way to write the isotopes in shorthand is as follows: CCl 12 6 35 17 The top number is the ________ #, and the bottom # is the __________ number. Calculating the # n 0 can be found by _____________ the #’s! protons neutrons mass masses neutrons atomic mass atomic subtracting

15. (1) Find the # e -, p + and n 0 for Xe-131. 2) Find the # e -, p + and n 0 for 3) Write a shorthand way to represent the following isotope: # e - = 1 # n 0 = 0 # p + = 1 Cu 63 29 Atomic # = 54 = p + = e − n 0 = 131 − 54 = 77 Atomic # = 29 = p + = e − n 0 = 63 − 29 = 34 Atomic # = p + = e − = 1 mass # = n 0 + p + = 1+ 0 = 1 H-1 orH 1 1

16. * Based on the relative mass of Carbon-12 which is exactly _______. * 1 p + ≈ __ atomic mass unit (amu) 1 n 0 ≈ __ amu 1e - ≈ __ amu * The atomic masses listed in the Periodic Table are a “weighted average” of all the isotopes of the element. 12 110 Weighted Average Practice Problems: (1) Mrs. Smith’s geometry semester grades are calculated using a weighted average of three category scores: Major Grades= 60% of your grade Minor Grades= 30% of your grade Semester Exam=10% of your grade If a student had the following scores, what would they receive for the semester? Major= 80 (B − ) Minor= 60 (D −) Semester Exam=65 (D)

17. Step (1): Multiply each score by the % that it is weighted. Step (2): Add these products up, and that is the weighted average! 60% x 80 = 48.0 30% x 60 = 18.0 10% x 65 = 6.5 Add them up!! A “normal average” would be calculated by simply adding the raw scores together and dividing by 3… 80 + 60 + 65 = 205 ÷ 3 = 68.3 = D + 72.5 (C−)

18. Practice Problems: (2) In chemistry, chlorine has 2 isotopes: Cl-35 (75.8% abundance) Cl-37 (24.23 % abundance) What is the weighted average atomic mass of chlorine? 35 x 0.758 = 26.53 37 x 0.2423 = 8.9651 Add them up!!! (3) Oxygen has 3 isotopes: O-16 (99.76%) O-17 (0.037%) O-18 (0.2%) Estimate oxygen’s average atomic mass. + 35.4951 amu Barely over 16.0 amu

19. (4) Copper has an average atomic mass of 63.546 amu. It contains only two natural isotopes, which are Cu-63, with an isotope mass of 62.940 and Cu-65 with an isotope mass of 64.928. What are the percent of the two isotopes in naturally occurring copper? Avg. Atomic Mass = (% Cu-63 x Mass Cu-63 ) + (% Cu-65 x Mass Cu-65 ) 63.546 = (% Cu-63 x 62.940) + (% Cu-65 x 64.928) % Cu-63 + % Cu-65 = 100% % Cu-63 + % Cu-65 = 1 OR

20. 1. 80% 127 I, 17% 126 I, 3% 128 I 2. 50% 197 Au, 50% 198 Au

21. Nucleons: particles in the nucleus (protons and neutrons) Nuclear Charge: charge of the nucleus (same at # of protons) Examples: 1. How many nucleons are there in an atom with an atomic number of 20 and 23 neutrons? 2. What is the nuclear charge of an Iron atom?

22. * An atom can gain or lose electrons to become electrically charged. * Cation = (___) charged atom created by ___________ e-’s. * Cations are ______________ than the original atom. * _____________ generally form cations. * Anion = (___) charged atom created by _____________ e-’s. * Anions are ____________ than the original atom. * _______________ generally form anions. Practice Problems: Count the # of protons & electrons in each ion. a) Mg +2 p + = _____ e − = ______ b) F −1 p + = _____ e − = ______ +losing smaller Metals −gaining larger Nonmetals 1210 9

23. Atomic Models (1) Model: a ball of (+) charge containing a number of e - no ________________ often described as the “________ _______________” atom. (2) Model: a ____________ of (+) charge surrounded by a number of e - no _____________ and no e - orbitals Thomson nucleus plum pudding Rutherford nucleus neutrons

24. (3) Model: a nucleus of (+) charge that also contains ______________ nucleus is encircled by e - ’s located in definite orbits (or paths). e - ’s have ___________ energies in these orbits e - ’s do not lose energy as they orbit the nucleus (4) Mechanical Model ( Wave Mechanical Model) no definite ____________ to the e - path (“fuzzy” cloud) orbits of e - ’s based on the _________________ of finding the e - in the particular orbital shape. Atomic Models Bohr neutrons fixed Quantum shape probability

26. Bohr Atomic Model

28. http://www.slideshare.net/laburkett/history-of-the-atom

30. * Heisenberg showed that the more precisely the momentum of a particle is known, the less precisely is its position known: * In many cases, our uncertainty of the whereabouts of an electron is greater than the size of the atom itself! (  x) (  mv)  h4h4

33. Quantum Mechanical Model

34. Diagram: The energy levels in an atom are sort of like _________ of a ladder. The more energy an electron has, the __________ away from the nucleus it usually will be. The energy levels are not evenly spaced. They get ___________ together as you travel farther away. To move from one “rung” to another requires a “____________” of energy. AIM: How can we describe where electrons are located? - Energy Levels rungs farther closer quantum

35. continuous energy levelsquantized energy levels

36. * Describe the ______________ of the e - ’s around the nucleus. * Quantum #’s are sort of like a home _____________ for the electron. * This information about the location of the e - ’s in an atom can be used to: (1) determine chemical & physical _____________ for the elements. (2) show how the _______________ __________ is organized. (3) show _____ and _____ elements combine to form compounds. location address properties Periodic Table howwhy

37. 1. Principal Q. #: Describes the _____________ that the electron is from the nucleus. The bigger the number, the ___________ away the electron is. Example: (1=closest, 2, 3, 4...farther away) These distances are sometimes called _______________ ______________ ____________. 1 2 3nucleus distance farther principal energy levels

38. 2. Orbital Q. #: Describes the __________ of the electron’s path around the nucleus with a letter: (s, p, d, & f) These are sometimes called “_____________”. s=_____________ cloud; p=_____________ or a 3-D figure 8; shape sublevels sphericalellipsoid

39. * d & f orbital shapes are complex ________- _______________ ellipsoids, and some d’s and f’s are an ellipsoid with a doughnut or two around the middle. * All of these orbital shapes are based on the probability of finding the electron in the cloud. d - orbitals f - orbitals criss crossing

40. s s s s p p p f d d

41. 1 sublevel 2 sublevels 3 sublevels

42. 3. Magnetic Q. #: tells how many _________________ in 3-D there are about the nucleus for each orbital shape. s=___ orientation p= ___ orientations... (x, y, and z) d= ___ orientations f= ___ orientations * The orientations are represented with a line or a box. Examples: ___This means a __________ orbital at a distance of 1s“__” (close) to the nucleus. This orbital is centered about the x, y, and z axis. □ □ □ This represents an ___________ orbital with its 4p ____ possible orientations at a distance of “___” from the nucleus. orientations 1 3 5 7 spherical ellipsoid 3 4 1

44. 4. Spin Q. #: describes how the electron in an orientation is spinning around the nucleus. This spin can be thought of as “____” or “________”. (Some like to imagine it spinning “clockwise” and “counterclockwise”.) The spin is represented as an ___________ in the direction of the spin. Example: ↑ This represents one electron in a _________ 2s orbital with spin “____” at a distance of “___”from the nucleus. * Remember, the four quantum numbers tell us the location, or “address” of each electron in an atom. * This information is vital in understanding the layout of the Periodic Table and the reasoning behind why and how atoms form bonds. up down arrow sphericalup 2

45. * Electron configurations are notations that represent the four Quantum #’s for all of the electrons in a particular atom. Here are the rules for these notations: * Rule #1 (Aufbau Principle): Electrons fill ________ energy orbitals first. Examples: 1s would be filled before ____ 3s would fill before ____ AIM: How can we describe how electrons are arranged? - Electron Configurations lowest 2s 3p

46. Electron Configurations (Energy Level Diagram) 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p… ↑↓ ↑ ↓ ↓ ↓ ↑ ↑ ↑ ↑ ↑↑↓↓ Silicon

47. * Rule #2: Only ___ electrons can fit into each orientation. Example: ___ ___ not ____ 1s 2s 1s * Rule #3 (Pauli Exclusion Principle): Electrons in the same orientation have ______________ spin. Example: ___ not ___ 1s 1s * Rule #4 (Hund’s Rule): “_______________ rule”---> Every “ □ ” in an orbital shape gets an electron before any orientation gets a second e -. Example: □□□ not □□□ 2p 2p ↓ ↓↑↑ 2 ↓↑↑ opposite ↑ ↑ ↑ Monopoly ↑ ↑ ↑ ↑ ↑ ↓

48. * Rule #5: The Exceptions * Half-filled or completely filled d & f sublevels have ________ energies and are more stable than partially filled d’s and f’s. * This means that an atom can “borrow” one of its “s” electrons from the previous orbital to become more stable. Example: ___ ___ ___ ___ ___ ___ 5s 4d becomes___ ___ ___ ___ ___ ___ 5s 4d * Because the 4d sublevel is now full, the atom is at a ________ energy state and therefore _________ stable. lower more ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↑

49. Electron Configurations (Energy Level Diagram) 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p… ↑↓ ↑ ↓ ↓ ↓ ↑ ↑ ↑ ↑ ↑↑↓↓ Silicon

50. Practice Problems: Write the electron configuration notation for each of the following atoms: * Hydrogen * Carbon * Iron * Bromine Shorthand Method: Assumes we already know about the # of □. * H * C * Fe * Br

51. s p d f

53. * How do electron configurations relate to the chemical and physical properties of an element? * All elements with the _________ outer shell e - configurations have ________ properties. * This means that elements in the same ____________ group have similar properties. Examples: (1) Li, Na, K, Rb, and Cs all have __ lone “__” e - for their last orbital... (_____, _____, _____, etc.) This makes all of them ___________ reactive. They all react with __________ to produce hydrogen gas. (2) Ne, Ar, Kr, Xe, and Rn all have the outer energy level completely __________ with electrons...(________, ________, ________, etc.) This makes all of them ______________. They do not produce __________________! same similar vertical 1s 2s 1 3s 1 4s 1 verywater filled2s 2 2p 6 3s 2 3p 6 4s 2 4p 6 inert compounds

54. More Practice Problems (1) Which element has its last electron as a 4p 5 ? ___________ (2) Which elements are similar in properties as Bromine? __________ (3) What would the outer shell electron configuration look like for the element underneath Radon, (Rn)? (4) Which electron is added after 6s 2 ? ________ (5) Which element would “borrow” a 5s electron to get a half-filled “d” sublevel? ___________ (6) What is the shape of the last orbital filled in Calcium, (Ca)? _____ (7) How many electrons are in the last “p-orbital” of Sulfur, (S)? ____ Bromine F, Cl, I, At …7s 2 5f 14 6d 10 7p 6 4f 1 Mo sphere 4

55. * Any wave of energy traveling at a speed of ___________ is called electromagnetic radiation. * There are many types of electromagnetic radiation and each type has a different _______________ and _______________. * Here are the types of electromagnetic radiation from longest to shortest wave or lowest to highest frequency. These are also in order from lowest to highest energy. light frequencywavelength

57. (1) Radio Waves -- used in __________________ (2) Microwaves-- broadcasts TV signals and used to _____ _______. (3) Infrared (IR) -- we feel this as _____; _________ & ______ can “see” this. infrared image of a cat infrared image of heating pipes under a floor heat cook food communications Snakesowls

59. (4) Visible Light -- the only radiation we can detect with our eyes. It can be separated into the colors of the spectrum with a __________. ROYGBIV (5) Ultraviolet (UV) -- gives you a _____________; _________ can “see” this; some of this radiation from the sun gets blocked by the ___________ layer flower photo under normal lightflower photo under UV light prism sunburnBees ozone

60. (6) X-rays -- used in medicine Ouch!

61. (7) Gamma Rays-- some radioactive substances give it off * _______________Rays – These are not part of the EM spectrum… They are high energy particles (mostly protons); They cause the northern lights. Interesting superhero facts: Superman has x-ray vision. The Incredible Hulk was “created” by an accidental overdose of gamma radiation. The Fantastic Four were “created” by cosmic rays. Cosmic

62. * When atoms get hit with energy (by _____________ them with electricity or by ____________ them up), the electrons absorb this energy and __________ to a higher energy level. Figure (a) * As they immediately fall back down to the “____________ state”, they give off this energy in the form of a particle of ___________ (or other types of electromagnetic radiation) called a _____________. Figure (b) zapping heating jump ground light photon

63. * Each photon emitted has a specific ___________ (or frequency). * The color of the light that is given off depends on how _____ the electron _______ (which depends on how big of a jump it originally made.) The farther the fall, the ___________ energy the photon has. color farfell greater

65. * Since electrons are located only in certain __________ levels (or orbitals) around the nucleus, only certain specific _________ of light are emitted. * Scientists use a _________________ to separate these colors into bands of light. These bands of color look like a ______ code of color which is characteristic of that element. No two elements produce the same ______________ of colors. This can be used to distinguish one element from another contained in a sample. (See Fig. 13.11) energy color spectroscope bar spectrum

66. Hydrogen Spectrum Neon Spectrum

67. * The photons of light given off or absorbed by atoms have specific energies that can be calculated according to the following formula: E=hν (E = h f…some textbooks write it this way.) E = energy (in joules) h = Planck’s constant = 6.63×10 −34 J·s ν (nu) = frequency of the light in units of Hertz (waves per second)…s -1 * The frequency of light can be determined if given the wavelength (in meters) according to the following formula: c=λν (c = f λ …some textbooks write it this way.) c = the speed of light = 3.0 x 10 8 m/s λ (lambda) = wavelength (in meters) Both of these equations are given to you on the AP Equation Sheet.

68. How hydrogen produces the four visible photons

69. All the Photons Produced by Hydrogen

70. * Louis de Broglie suggested that if light can have material properties, matter should exhibit wave properties. * He demonstrated that the relationship between mass and wavelength was * h = Planck’s constant and v = velocity * Quantity mv is called its momentum = h mv

71. http://www.brainpop.com/science/matterandchemistr y/atomicmodel/