Chemistry Day 17. Friday, October 5 th Monday, October 8 th, 2018

Transcription

1 Chemistry Day 17 Friday, October 5 th Monday, October 8 th, 2018

2 Do-Now: Unit 1 Test Day Do-Now 1. Write down today s FLT 2. Write down one question you have about the test (topic-wise or format-wise). 3. The change from a solid to a is called. 4. When doing calculations, I need to always include. 5. Correct Dalton by completing the sentence frame: While I agree that atoms of the same element, I disagree that because atoms of the same element can. 6. What should you always remember when solving half-life problems? 7. Take five minutes to review for the test. Take out your planner and ToC

3 Chemistry Day 18 Tuesday, October 9 th Wednesday, October 10 th, 2018

4 Do-Now: Ch. 11 Demo 1. Write down today s FLT 2. Distinguish between subatomic particles and nucleons 3. What do protons and neutrons have in common? 4. What do electrons and protons have in common? 5. Use a pro-talk sentence frame to explain something about subatomic particles. 6. We will do our demo notes under this do-now Take out your planner and ToC

5 Demo I have a plasma ball and two types of lights/bulbs. Underneath your do-now Use your pro-talk sentence frame In my opinion because to make a prediction about what you THINK will happen.

6 Demo Now, write down three questions you have about the demo.

7 Demo Discuss your questions with your group. Decide as a group which question is the best or the most interesting, and everyone should write it on their paper. What do you think we saw?

8 Demo Now, we will watch a video. During the video, write down one or two pieces of evidence that can help you explain what s happening.

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10 Demo Use the information from the video and the demo to answer your question. Use one of the following pro-talk sentence frames: First I considered, then... Proves my claim because If we look at both. and. We can see that. Based on the evidence, we can conclude that.

11 FLT I will be able to diagram and describe Bohr s atomic model by completing Ch. 11 Notes A Standard HS-PS1-1: Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms

12 Notes Protocol Title your notes & add assignment # Complete Cornell-style Copy down all bolded ideas Noise level 0 Raise hand to question/comment Be prepared to pair-share-respond

13 Ch. 11 A: Bohr s Atomic Model

14 Draw 5 circles on your notes

15 Recall Atomic models so far: Dalton Thomson Rutherford

16 Atomic Models:

17 Atomic Models:

18 Atomic Models:

19 Rutherford s Atomic Model What was inadequate about Rutherford s atomic model?

20 Rutherford s Atomic Model It could not explain the behavior of e - s or the chemical properties of elements The behavior of electrons is important to understanding the physical properties of elements, such as why objects change color when heated.

21 Bohr Atomic Model

22 Electron Cloud/Quantum Model

23 The Bohr Model What was the new proposal in the Bohr model of the atom?

24 The Bohr Model Bohr tried to explain the behavior of electrons Why didn t electrons crash into the nucleus?

25 The Bohr Model An e - is found only in specific circular paths (energy levels) around the nucleus.

26 The Bohr Model Energy Levels = e - s have fixed energies for each orbit

27 The Bohr Model Quantum of energy = The amount of energy required to move an e - from one E level to another

28 The Bohr Model e - s absorb energy when they move to a higher E level

29 The Bohr Model e - s emit E when they move to a lower E level

30 Bohr Model

31 The Bohr Model Like the rungs of the strange ladder, the energy levels in an atom are not equally spaced. Higher energy levels require less energy for an e - to move up

32 Pair-Share-Respond 1. What are the four models of the atom that we have learned about so far? 2. What was an issue with Rutherford s model? 3. Describe Bohr s model of the atom 4. When do electrons absorb energy, and when do they emit energy? 5. How are higher energy levels different than lower energy levels?

33 Chemistry Day 19 Thursday, October 11 th Friday, October 12 th, 2018

34 Do-Now: Atomic Orbital WS 1. Write down today s FLT 2. What was wrong with Rutherford s atomic model? 3. Sketch a diagram of Bohr s model. Label it. 4. Summarize Bohr s model in 1-2 sentences. 5. Explain what happens when electrons move up or down an energy level. We will use this paper for our classwork after our notes, so keep it accessible Take out your planner and ToC

35 FLT I will be able to describe the electrons of an atom using the quantum atomic model by completing Ch. 11 Notes B Standard HS-PS1-1: Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.

36 Notes Protocol Add assignment # Copy down words or expressions that go in the blank spaces on the worksheet Noise level 0 Raise hand to question/comment Be prepared to pair-share-respond

37 Ch. 11 B: Quantum Atomic Model

38 Atomic Models

39 Need for a New Model

40 Bohr Model Shortcomings of the Bohr Model: e - s can t orbit the nucleus Did not explain the properties of larger atoms à only explained the behavior of hydrogen atoms

41 The Quantum Mechanical Model A new model needed to be developed to explain the forces and behavior of atoms

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43 Quantum Mechanical Model

44 Quantum Model

45 The Quantum Mechanical Model The quantum mechanical model is based on quantum theory Scientists, such as Schrödinger, noted that matter can behave like waves, and developed complex mathematical equations that could describe the behavior of e - s

46 The Quantum Mechanical Model Quantum Theory and Heisenberg: Uncertainty Principle = it s impossible to know both the exact position and momentum of an e - at the same time

47 The Quantum Mechanical Model Quantum Mechanical Model Determines the allowed energies an e - can have and how likely it is to find the e - in various locations around the nucleus

48 The Quantum Mechanical Model In the quantum mechanical model, the probability of finding an electron within a certain volume of space surrounding the nucleus can be represented as a fuzzy cloud The cloud is more dense where the probability of finding the electron is high.

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50 The Quantum Mechanical Model Instead of orbits, the model uses orbitals Atomic Orbitals = regions of space in which there is a high probability of finding an e - Orbitals are sometimes called e - clouds

51 Atomic Orbital Shapes Each type can hold up to TWO electrons

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54 Quantum Model

55 Pair-Share-Respond 1. What was wrong with Bohr s atomic model? 2. State the uncertainty principle. 3. What does the quantum model use instead of orbits? 4. Define the term atomic orbital 5. Are atomic orbitals actually part of an atom?

56 Quantum Numbers

57 Quantum Numbers Four numbers, called quantum numbers, describe the characteristics of electrons and their orbitals

58 Quantum Numbers n = Principal Quantum Number l = Angular Momentum Quantum Number m l = Magnetic Quantum Number m s = Spin Quantum Number

59 Quantum Numbers n = Principal Quantum Number n represents the specific energy level and the size of the orbital (higher energy levels are larger) n = 1, 2, 3, Ex/ n=2 means electrons in the 2 nd energy level/shell n=3 means? n=5 means?

60 Quantum Numbers n = Principal Quantum Number The total number of e - s that an energy level can hold is 2n 2 Ex/ n=2 is the 2 nd energy level. It can hold 2(2) 2 electrons à 8 electrons total How many electrons can be on the 3 rd energy level?

61 Quantum Numbers l = Angular Momentum Quantum Number This specifies the shape of the orbital: s, p, d, or f l = 0,, n-1 Ex/ if n=1, then l = 0 à s orbitals Ex/ If n = 3? l = 0 l = 1 l = 2 l = 3 s p d f

62 Quantum Numbers l = Angular Momentum Quantum Number If n = 2, l can be 0 or 1 (up to n-1) If n = 3, l can be 0, 1, or 2 If n = 4? l = 0 l = 1 l = 2 l = 3 s p d f

63 Quantum Numbers

64 Quantum Numbers Ex/ If n = 3 and l = 0, then it is the 3s subshell This means the s orbital on the 3 rd energy level Ex/ If n = 2 and l = 1, then It is the 2p subshell Ex/ If n = 4 and l = 2, then It is the 4d subshell

65 Quantum Numbers m l = Magnetic Quantum Number Describes the orientation of the orbitals May be l, 0, +l Ex/ n = 2 and l = 1 à so m l = -1, 0, +1 (3 orbitals) What if n = 3 and l = 2?

66 Quantum Numbers m l = Magnetic Quantum Number Just remember: s subshell has one orbitals p subshell has three orbitals d subshell has five orbitals f subshell has seven orbitals

67 Quantum Numbers m s = Spin Quantum Number This describes the direction of the electron either clockwise or counterclockwise Only two values: +1/2 or -1/2 Therefore, there can only be up to two e - s in each subshell/specific orbital with opposite spins Ex/ One s orbital can hold up to TWO electrons Ex/ One p orbital can hold up to TWO electrons Ex/ One f orbital can hold up to you guessed it TWO electrons

68 Note: The fewer the quantum numbers, the less we know about the electrons. Ex/ If n = 3, I could be talking about 2n 2 or 18 electrons on the 3 rd energy level The MORE quantum numbers we have, the more we know about the electrons. Ex/ If n = 3 and l = 2, I could be talking about any electrons in the d orbitals. Since there are 5 d orbitals, this means I could be talking about 10 electrons. Ex/ If n = 3, l = 2, and m l = 0, then I am talking about one specific d orbital, and therefore 2 electrons. Ex/ If n = 3, l = 2, m l = 0, and m s = + ½, then I am only talking about one electron.

69 Atomic Orbitals Different atomic orbitals are denoted by letters. The s orbitals are spherical, and p orbitals are dumbbell-shaped.

70 Atomic Orbitals Four of the five d orbitals have the same shape but different orientations in space.

71 Atomic Orbitals The numbers and kinds of atomic orbitals depend on the energy sublevel.

72 Pair-Share-Respond 1. List the names and symbols of the four quantum numbers 2. What are the possible m s values? 3. Explain the meaning of n =3 and l = 2 4. If n = 3 and l = 2, How many total orbitals will there be? 5. If n=3, How many total electrons can there be?