WARM-UP. Draw each of the three models of the atom that we learned about last unit. Who came up with each? What was wrong with each?

Transcription

1 WARM-UP Draw each of the three models of the atom that we learned about last unit. Who came up with each? What was wrong with each? 1:59 1:58 1:57 1:56 1:55 1:54 1:53 1:52 1:51 1:50 1:49 1:48 1:47 1:46 1:45 1:44 1:43 1:42 1:41 1:40 1:39 1:38 1:37 1:36 1:35 1:34 1:33 1:32 1:31 1:30 1:29 1:28 1:27 1:26 1:25 1:24 1:23 1:22 1:21 1:20 1:19 1:18 1:17 1:16 1:15 1:14 1:13 1:12 1:11 1:10 1:09 1:08 1:07 1:06 1:05 1:04 1:03 1:02 1:01 1:00 0:59 0:58 0:57 0:56 0:55 0:54 0:53 0:52 0:51 0:50 0:49 0:48 0:47 0:46 0:45 0:44 0:43 0:42 0:41 0:40 0:39 0:38 0:37 0:36 0:35 0:34 0:33 0:32 0:31 0:30 0:29 0:28 0:27 0:26 0:25 0:24 0:23 0:22 0:21 0:20 0:19 0:18 0:17 0:16 0:15 0:14 0:13 0:12 0:11 0:10 0:09 0:08 0:07 0:06 0:05 0:04 0:03 0:02 0:01 2:00 End

2 UNIT 2 NOTES QUANTUM THEORY & PERIODIC TABLE S U B T I T L E

3 Q U A N T U M T H E O R Y

4 WHAT DO YOU SEE?

5 LIGHT Light is a particle AND a wave, at the same time Electromagnetic radiation energy that exhibits wavelike behavior as it travels through space. Visible light is only one example

6 ELECTROMAGNETIC SPECTRUM

7 PROPERTIES OF WAVES All light has a speed (c) of 3.0x10 8 m/s Wavelength (λ) length of one complete wave Frequency (ν) number of waves that pass a point during a certain time period Hertz (Hz) = 1/s Amplitude (A) distance from the origin to the trough or crest

8 WAVES

9 PRACTICE

10 PRACTICE Looking at EM spectrum, which form of radiation has the: Longest wavelength? Highest frequency? Highest energy?

11 PRACTICE Which form has the longer wavelength? Violet or green Blue or red Ultraviolet or infrared Ultraviolet or visible Infrared or visible Orange or yellow?

12 ELECTROMAGNETIC SPECTRUM

13 ELECTROMAGNETIC SPECTRUM

14 WAVE CALCULATIONS c = λν c = speed of light (3.0 x 10 8 m/s) λ = wavelength (m, nm, etc.) ν = frequency (Hz or /s or s -1 )

15 WAVE CALCULATIONS Microwaves are used to transmit information. What is the wavelength of a microwave having a frequency of 3.44 x 10 9 Hz?

16 WAVE CALCULATIONS What is the frequency of green light that has a wavelength of 4.9 x 10-7 m?

17 WAVE VARIABLE RELATIONSHIPS How is frequency related to wavelength? How is frequency related to energy? How is wavelength related to energy?

18 QUANTUM THEORY Max Planck (1900) Observed the emission of light from hot objects Photoelectric effect the emission of electrons from a metal when light shines on the metal Light has to have a minimum frequency in order for the photoelectric effect to occur!

19 QUANTUM THEORY Max Planck (1900) He suggested that an object emits energy in small, specific amounts, called quanta Quantum the minimum quantity of energy that can be lost or gained by an atom

20 QUANTUM THEORY

21 QUANTUM THEORY Einstein(1905) Light is a particle AND a wave! wave-particle duality Photon particle of light having zero rest mass and carrying a quantum of energy

22 WHAT DO YOU SEE?

23 MORE CALCULATIONS E photon = hν E = energy (J, joules) h = Planck s constant ( x J s) ν = frequency (Hz or /s or s -1 )

24 WAVE CALCULATIONS What is the energy of a photon from the violet portion of the rainbow if it has a frequency of 7.23 x s -1?

25 BOHR S MODEL OF THE ATOM What was wrong with Rutherford s model?

26 BOHR S MODEL OF THE ATOM Bohr accounted for that problem! Electrons exist only in orbits with specific amounts of energy called energy levels

27 ATOMIC EMISSION SPECTRA Some definitions: Ground state: the lowest state or energy of an atom Excited state: a state in which an atom has a higher potential energy than its ground state (this is when an atom GAINS energy)

28 BOHR S MODEL OF THE ATOM The smaller the electron s orbit, the lower the atom s energy state Each orbit has a quantum number (n) When an electron moves to a HIGHER energy level energy is put IN When an electron drops to a LOWER energy level, a photon is EMITTED (light)

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31 BOHR S MODEL OF THE ATOM Each element has a unique bright-line emission spectrum Sad news? Bohr s calculations only worked for hydrogen

32 MODERN QUANTUM MODEL OF THE ATOM DeBroglie s Hypothesis (1923): If waves can behave like particles, then maybe particles (e - ) can behave like waves. Wave-particle duality

33 MODERN QUANTUM MODEL OF THE ATOM Heisenberg s Uncertainty Principle (1927) It is impossible to know both the position and velocity of an e - at the same time.

34 MODERN QUANTUM MODEL OF THE ATOM Schrodinger s Wave Equation (1926) Treat the electron as a wave He developed an equation used to determine the probability of finding the e - in any given place around the nucleus. If these probabilities are plotted in 3D, the probability area becomes a cloud.

35 THE QUANTUM MODEL

36 THE QUANTUM MODEL

37 QUANTUM NUMBERS What are they? Values that represent different electron energy states and the most probable place to find an electron

38 PRINCIPAL QUANTUM NUMBER n Represents the cloud size (distance from the nucleus) Main energy level n 7 See row on the periodic table As n, size, Energy

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40 SECOND QUANTUM NUMBER l l = 0 n 1 Number of sublevels in a level = n Represents sublevels within an electron cloud s,p,d,f (order of increasing energy)

41 ORBITALS s orbital Sphere l = 0 One orientation p orbitals Peanut l = 1 Three orientations

42 ORBITALS d orbitals l = 2 Five orientations f orbitals l = 3 Seven orientations

43 THIRD QUANTUM NUMBER m l m l = +l l Represents the orbitals within sublevels s 1 orbital m l = 0 p 3 orbitals m l = 1, 0, +1 d 5 orbitals m l = 2, 1,0, +1, +2 f 7 orbitals m l = 3, 2, 1,0, +1, +2, +3

44 FOURTH QUANTUM NUMBER m s = ± 1 2 Only two electrons can occupy an orbital at the same time Represents the spin of the electron (clockwise or counterclockwise) Electrons in the orbital must have opposite spin

45 Principal Energy Level Number of Sublevels Number of Orbitals per sublevel Number of Electrons per Sublevel Maximum Number of Electrons per Energy Level

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47 EXAMPLES Name the orbitals described by the following quantum numbers n = 3, l = 1 n = 4, l = 2 n = 6, l = 0 Give the n and l values for the following orbitals 2p 4f

48 WARM-UP What are the possible m l values for l = 2? Which type of orbital is this? What are the four quantum numbers for the last electron of potassium (K)? 0:59 0:58 0:57 0:56 0:55 0:54 0:53 0:52 0:51 0:50 0:49 0:48 0:47 0:46 0:45 0:44 0:43 0:42 0:41 0:40 0:39 0:38 0:37 0:36 0:35 0:34 0:33 0:32 0:31 0:30 0:29 0:28 0:27 0:26 0:25 0:24 0:23 0:22 0:21 0:20 0:19 0:18 0:17 0:16 0:15 0:14 0:13 0:12 0:11 0:10 0:09 0:08 0:07 0:06 0:05 0:04 0:03 0:02 0:01 1:00 End

49 WHEN FIGURING OUT WHERE ELECTRONS GO IN AN ATOM, THE FOLLOWING RULES MUST BE FOLLOWED

50 PAULI S EXCLUSION PRINCIPLE No two e - in the same atom can have the same set of four quantum numbers. If 2 electrons occupy the same orbital, they must have opposite spin

51 AUFBAU PRINCIPLE building up Electrons occupy lowest energy level available Begin with the 1s orbital Sublevels overlap beginning with 3d How do you know the order of energy?

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53 HUND S RULE fair share Each orbital in a sublevel must have one electron before any orbital in that sublevel receives a 2 nd.

54 ORBITAL NOTATION Used to show exactly where all electrons are in an atom An orbital is represented by a circle, line, or box Up and down arrows represent electrons with opposite spin

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56 WARM-UP List all the quantum numbers for n=1 What about n=2 Write out the electron configuration and orbital notation for phosphorus What is the noble gas configuration for iodine?

57 QUANTUM NUMBERS

58 If more help/clarification is needed

59 ELECTRON CONFIGURATION The numbers in front of the sublevel letters represent the energy level The exponents refer to the number of electrons in that sublevel. The sum of the exponents should equal the atomic number of the element

60 VALENCE ELECTRONS Electrons found in the outermost energy level These electrons are involved in bonding Since the d and f orbitals have higher energy due to overlap, s and p orbitals contain valence electrons Maximum and desired amount of valence e - is 8 Except H, He, Li, and Be (only have 2)

61 LEWIS ELECTRON DOT DIAGRAM The dots around the element symbol represent only valence electrons.

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63 P E R I O D I C TA B L E

64 ELEMENT SUPERHERO PROJECT Three Easy Steps. 1. Choose one element from the periodic table and research it. 2. Create a super hero that represents that element and its unique qualities. 3. Design a comic depicting your superhero and name. 4. Print out instructions and follow closely 5. Complete the required worksheet DUE: Wednesday, September 21, 2016

65 LAVOISER (1790 S) Composed a list of known elements (23 elements) Including oxygen, carbon, gold and silver

66 NEWLANDS Organized elements by increasing atomic mass The law of octaves

67 MENDELEEV (1869) Organized the first periodic table by increasing atomic mass Connection between atomic mass and elemental properties Predicted properties of undiscovered elements (like scandium, gallium and germanium)

68 PERIODIC TABLE OF ELEMENTS

69 MOSELEY Henry Mosley- arranged the Periodic Table by atomic number. Atomic number = number of Protons TODAY! The periodic table is still organized by atomic number. Periodic Law: the statement that there is a periodic repetition of chemical and physical properties of elements when they are arranged by increasing atomic number

70 PERIODIC TABLE OF ELEMENTS

71 PERIODIC TABLE OF ELEMENTS Groups Periods Valence Electrons

72 GROUPS

73 GROUPS Elements in the same groups have the same number of VALENCE ELECTRONS! Valence electrons are the outer most electrons on an atom. They control how the atoms attach to each other.

74 PERIODS

75 PERIOD All of the elements in a period have the same number energy levels.

76 SECTIONS IN THE PERIODIC TABLE Alkali metals Alkaline earth metals Transition metals Halogens Noble gases Lanthinides Actinides Metals Non-metals Metalloids

77 CREATE A PAPER SLIDE VIDEO Each group (of approximately 4 people) will receive one of these families (listed above) and create a presentation based on each family. This presentation will then be presented to the class. Each group will TEACH the class about their particular Periodic Table Family. Each project will contain: 3 characteristics of the periodic family where they can be found on earth (if they are found on earth) how many valence electrons and/or what charge at least 2 ways the family is used by humans.

78 20 Research Did you provide hardcopies of research? 10 Complexity How much effort (Thinking or Artistic) did you put into your project? 10 Creativity How creative is your idea? How creative did you get with your project itself? 10 Presentation Did you present your project? Did you speak clearly, animatedly, and loudly? 10 Final Product What does it look like? How neat is it? Number of Points Category 40 Completion Did you turn in a completed project? Did it include 3 characteristics, where they can be found, how many valence electrons, and 2 ways it is used by humans?

79 METALS Malleable Ductile Conduct electricity Lustrous Metallic bonding

80 ALKALI METAL GROUP 1A Soft Most reactive metals Group 1 One valence electron Forms ions with a +1 charge Reactive violently with water. Francium is even radioactive!

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82 ALKALINE EARTH METALS GROUP 2A Are very reactive. Density greater than group 1 Hardness greater than group 1 Less reactive than group 1 Two valence electrons Forms ions with a +2 charge Used in fireworks, batteries, and your body!

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84 TRANSITION METALS D BLOCK Form colored ions in solution. Copper is blue or green More than one charge. Copper can be +1 or +2 Most widely used by Humans Iron, Nickel, Copper, Gold, etc.

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86 LANTHANIDES Rare earth metals Similar to group 2 in characteristics Top row of F block

87 ACTINIDES Radioactive Bottom row of F block

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89 METALLOIDS Exhibit characteristics from both metals and nonmetals. Semiconductors. Boron, Silicon, Germanium, Arsenic, Antimony, and Tellurium On staircase (except Aluminum)!

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91 INNER TRANSITION METALS Lanthanides and Actinides Located outside of the periodic table. Often used with light and film. Uranium is in this section Used for nuclear power.

92 HALOGENS GROUP 7A Most reactive nonmetals Called salt formers Forms ions with a -1 charge 7 valence electrons Bromine and iodine are used in halogen headlights Halogens form salts when forming an ionic bond with a metal.

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94 NOBLE GASES GROUP 18 All of these elements are gases. Do NOT interact with other elements - Inert Why? Because they have a FULL valence/outer shell.

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96 OTHER GROUPS Other groups in the table are named by the element at the top of the table. Some group are mixed with metals and nonmetals. Which two groups are most mixed?

97 ATOMIC RADIUS Defined by how close one atom is to another Rule: Atomic radius increases as you go DOWN a group and decreases as you go to the RIGHT along a period Why?? Because as you go down a group you increase the number of energy levels As you go across radius decreases because you are increasing protons causing a greater pull on the electrons

98 ATOMIC RADIUS

99 ATOMIC RADIUS What has the largest atomic radius: carbon, fluorine, beryllium or lithium? Which has the largest radius: Mg, Si, S, Na?

100 IONIC RADIUS When atoms LOSE electrons, they become smaller When atoms GAIN electrons, they become larger The rule: Increases as you go DOWN a group and decreases as you go to the RIGHT along a period Cations < neutral atoms < anions

101 IONIC RADIUS Which substance is larger? Calium or calcide ion? Fluorine or fluoride ion?

102 ELECTRONEGATIVITY The ability of an atom to attract an electron. Fluorine has the highest electronegativity. The Rule: Decreases DOWN a group and increases across the period. The noble gases have a electronegativity of zero. Why?

103 ELECTRONEGATIVITY

104 ELECTRONEGATIVITY Rank the following elements by increasing electronegativity: sulfur, oxygen, neon, and aluminum

105 IONIZATION ENERGY The energy it takes an atom to lose an electron. The alkali metals have a very low ionization energy, because they want to lose an electron to have a full outer shell. The halogens have a very high ionization energy. The noble gases have the highest (Helium the highest of all of them) because they want to keep all of their electrons so they keep their outer shell. **More valence electrons = higher ionization energy

106 IONIZATION ENERGY

107 REACTIVITY - METALS The most reactive metal on the periodic table is Francium Metals want to give their electrons away The lower the ionization energy and the electronegativity, the more reactive a metal is

108 REACTIVITY - NONMETALS The most reactive metal on the periodic table is Fluorine Nonmetals want to gain electrons The higher the ionization energy and the electronegativity, the more reactive a metal is