Key Terms and Definitions

Transcription

1 Topic: Atomic Structure Duration: Traditional (50 minute periods) : 8-13 days (adjust to student needs using professional discretion) Block Schedule (90 minute periods) : 3-5 days (adjust to student needs using professional discretion) Eligible Content This is what the State of Pennsylvania wants your students to know and be able to do by the end of the unit. CHEM.A.2.1.1: Describe the evolution of atomic theory leading to the current model of the atom based on the works of Dalton, Thomson, Rutherford, and Bohr. CHEM.A.2.1.2: Differentiate between the mass number of an isotope and the average atomic mass of an element. CHEM.A.2.2.1: Predict the ground state electron configuration and/ or orbital diagram for a given atom or ion. CHEM.A.2.2.3: Explain the relationship between the electron configuration and the atomic structure of a given atom or ion (e.g. energy levels and/ or orbitals with electrons, distribution of electrons in orbitals, shapes of orbitals). CHEM.A.2.2.4: Relate the existence of quantized energy levels to atomic emission spectra. CHEM.B.1.1.1: Apply the mole concept to representative particles (e.g., counting, determining mass of atoms, ions, molecules, and/or formula units). CHEM.B.1.2.2: Apply the law of definite proportions to the classification of elements and compounds as pure substances. Performance Objectives These are examples, created by SDP teachers, of how you may translate the eligible content into learning goals for your classroom. 1. SWBAT connect important discoveries, experiments, and models used in the investigation of atomic structure IOT construct a timeline describing the evolution of the current view of the atom. 2. SWBAT use experimental evidence and observations, e.g. flame tests and static electricity, IOT explain the existence of subatomic particles. 3. SWBAT name the charges, masses, and arrangement of protons, neutrons, and electrons IOT summarize the structure of the atom and how the subatomic particles interact. 4. SWBAT recognize symbols of common elements IOT understand what they represent at the particulate level. 5. SWBAT determine an element s electron configuration IOT predict how that element will react. 6. SWBAT utilize Avogadro's number IOT determine the amount of atoms in a mass. 7. SWBAT use molar mass IOT calculate the amount in grams per mole of a substance. Key Terms and Definitions 1. atom - smallest unit of element that maintains properties of that element 2. atomic theory - all matter is composed of discrete units called atoms 3. atomic mass - the mass of an atom expressed in atomic mass units 4. atomic number - the number of protons in the nucleus of an atom; the atomic number is the same for all atoms of an element; this number defines the element. 5. electron configuration - the arrangement of electrons in an atom 6. electron - a subatomic particle that has a negative charge 7. excited state - a state in which an atom has more energy than it does at its ground state 8. ground state - the lowest energy state of a quantized system 9. isotope - an atom that has the same number of protons (atomic number) as other atoms of the same element do but that has a different number of neutrons 10. mass number - the sum of the numbers of protons and neutrons in the nucleus of an atom 11. neutron - a subatomic particle that has no charge and that is found in the nucleus of an atom 12. nucleus - in physical science, an atom s central region, which is made up of protons and neutrons 13. orbital - a region in an atom where there is a high probability of finding electrons 14. proton - a subatomic particle that has a positive charge and that is found in the nucleus of an atom; the number of protons of the nucleus is the atomic number, which determines the identity of an element

2 15. Law of definite proportions - a chemical compound always contains the same elements in exactly the same proportions by weight or mass. 16. Law of conservation of mass - mass cannot be created nor destroyed; only transformed. 17. Law of multiple proportions - when two elements combine to form two or more compounds, the mass of one element that combines with a given mass of the other is in the ratio of small whole numbers. 18. Coulomb s law - the closer two charges are, the greater the force between them. 19. Quantum number - one of four values that defines the properties of an electron. 20. Pauli exclusion principle - Two particles of a certain class cannot be in the exact same energy state. 21. Aufbau principle - The structure of each successive element is obtained by adding one proton to the nucleus of the atom and one electron to the lowest-energy orbital that is available. 22. Hund s rule - For an atom in the ground state, the number of unpaired electrons is the maximum possible and these unpaired electrons have the same spin. 23. Mole - The SI base unit used to measure the amount of a substance whose number of particles is the same as the number of atoms in 12 g of carbon Molar Mass - The mass in grams of 1 mole of a substance. 25. Avogadro s number X 10 23, the number of particles in one mole Starting Points An overview of how the content and skills of this unit connect to students' prior knowledge. After completing an introductory unit on matter, students will revise their understanding about the particulate view of matter to include subatomic particles with special emphasis on electrons and electron configurations. The history of our knowledge of the atom, along with models we ve used to understand and visualize the atom s structure, can act as a framework for understanding atomic structure. Students should be familiar with the periodic table and be able to extract information regarding atomic number and mass from it, with periodic trends being covered in the next unit. Students will also be introduced to the concept of the mole and Avogadro s number and be able to make mass and / or particle conversions. Instructional Resources Learning activities and resources targeted to the eligible content of this unit. 1. SWBAT connect important discoveries, experiments, and models used in the investigation of atomic structure IOT construct a timeline describing the evolution of the current view of the atom. a. Holt Ch. 3 pp b. Vocabulary: atom, atomic theory, law of definite proportions, law of conservation of mass, law of multiple proportions c. Concept review worksheets Holt Ch 3 d. Ck12 link: Dalton and Democritus: e. Philadelphia Core Curriculum Resources (Spiral Bound green book): Atoms and Dalton s Theory pp f. PA Standards with linked Materials and Resources from PDESAS: 3.2.C.A5 2. SWBAT use experimental evidence and observations, e.g. flame tests and static electricity, IOT explain the existence of subatomic particles. a. Holt Ch. 3 pp b. Vocabulary: atom, proton, electron, neutron, nucleus c. Ck12 link: Cathode Ray Demonstration: Tube/lecture/Cathode-Ray-Tube-and- Electron/?referrer=concept_details&conceptLevel=&conceptSource=ck12 d. Concept review worksheets holt ch 3 e. Flame Test Lab sheet i. Screencast for flame test lab

3 f. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. Thomson s Atomic Model and Rutherford s Experiment pp ; ii. Rutherford s Atomic Model and the Bohr Hydrogen Model pp ; iii. Flame Test Lab pp g. PA Standards with linked Materials and Resources from PDESAS: 3.2.C.A6 3. SWBAT name the charges, masses, and arrangement of protons, neutrons, and electrons IOT summarize the structure of the atom and how the subatomic particles interact. 4. SWBAT recognize symbols of common elements IOT understand what they represent at the particulate level. a. (Objective 3 and 4 are related) b. Holt Ch. 3 pp c. Vocabulary: Atomic mass, atomic number d. Concept review worksheets holt ch 3 e. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. Bohr Hydrogen Model pp ; Chemical Symbols pp.58-59; ii. Calculating and Identifying Mass Number and Atomic Number pp SWBAT determine an element s electron configuration IOT predict how that element will react. a. Holt Ch. 3 pp b. Vocabulary: excited state, gruond state, orbital, Coulomb s law, quantum number, pauli exclusion principle, aufbau principle, hund s rule c. Concept review worksheets holt ch 3 d. Advanced topic: Use aufbau diagram and Hund s Rule to determine the 4 quantum numbers of an electron; and predict magnetic properties of elements. e. Literacy Link: Quantum Computers Explained Limits of Human Technology (video) f. Literacy Link: What is A Superconductor and Quantum Levitation? (video) g. Ck12 link: Electron Configuration: h. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. Light and Wave Properties pp ; ii. Heisenberg Uncertainty Principle & Pauli Exclusion Principle pp ; iii. Hund s Rule and Aufbau Principle & Writing Electron Configurations pp ; iv. Writing Electron Configurations & Lewis Structures pp i. PA Standards with linked Materials and Resources from PDESAS: 3.2.C.A2 6. SWBAT utilize Avogadro's number IOT determine the amount of atoms in a mass. 7. SWBAT use molar mass IOT calculate the amount in grams per mole of a substance. a. (Objectives 6 and 7 are related) b. Holt Ch. 3 pp c. Vocabulary: mole, molar mass, avogadro s number d. Concept review worksheets holt ch 3 e. PA Standards with linked Materials and Resources from PDESAS: 3.2.C.A2 Textbook References You must be logged into Schoolnet in order to access the online teacher text. Myers, Thomas R.; Oldham, Keith B.; and Tocci, Salvatore Dobson, K., Holman, J., & Roberts, M. (2004). Holt Chemistry. Austin, TX: Holt, Rinehart and Winston. Ch. 3, pp Holt Chemistry Textbook Resources Concept review worksheets holt ch 3

4 Additional laboratory Flame Test Lab sheet Screencast for flame test lab Suggested Advanced Topics: Use aufbau diagram and Hund s Rule to determine the 4 quantum numbers of an electron; and predict magnetic properties of elements. Philadelphia Core Curriculum Resources (Spiral Bound green book) 1. Atomos and Dalton s Theory pp Thomson s Atomic Model and Rutherford s Experiment pp Rutherford s Atomic Model and the Bohr Hydrogen Model pp Bohr Hydrogen Model pp Chemical Symbols pp Calculating and Identifying Mass Number and Atomic Number pp Isomers pp Light and Wave Properties pp Flame Test Lab pp Heisenberg Uncertainty Principle & Pauli Exclusion Principle pp Hund s Rule and Aufbau Principle & Writing Electron Configurations pp Writing Electron Configurations & Lewis Structures pp Exams Exam Ch 3 (4 versions) Answer Sheet for Exam Ch 3 Literacy Links Quantum Computers Explained Limits of Human Technology (video) What is A Superconductor and Quantum Levitation? (video) CK12 Links Electron Configuration: Dalton and Democritus: Story/?referrer=concept_details&conceptLevel=&conceptSource=ck12 Cathode Ray Demonstration: PA Standards with linked Materials and Resources from PDESAS 3.2.C.A2: Compare the electron configurations for the first twenty elements of the periodic table. Use the mole concept to determine number of particles and molar mass for elements and compounds. 3.2.C.A5: 1. Recognize discoveries from Dalton (atomic theory), Thomson(the electron), Rutherford(the nucleus), and Bohr (planetary model of atom) and understand how each discovery leads to modern theory. 2. Describe Rutherford s gold foil experiment that led to the discovery of the nuclear atom. Identify the major components (protons, neutrons, and electrons) of the nuclear atom and explain how they interact. 3.2.C.A6: Compare and contrast scientific theories. Know that both direct and indirect observations are used by scientists to study the natural world and universe. Identify questions and concepts that guide scientific investigations.

5 Formulate and revise explanations and models using logic and evidence. Recognize and analyze alternative explanations and models. Explain the importance of accuracy and precision in making valid measurements. Examine the status of existing theories. Evaluate experimental information for relevance and adherence to science processes. Judge that conclusions are consistent and logical with experimental conditions. Interpret results of experimental research to predict new information, propose additional investigable questions, or advance a solution. Communicate and defend a scientific argument. Periodic Table: ************************************************************************************************* Enrichment - Enroll your students into a Philadelphia tradition - Carver Science Fair ************************************************************************************************* Sample Questions from PDESAS Assessment Creator, Diagnostic Section: Chemistry 1.The table below gives information about the nucleus of each of four atoms. How many different elements are represented by the nuclei in the table? (1) 1 (2) 2 (3) 3 (4) 4 2. Which subatomic particle is negatively charged? (1) electron (2) neutron (3) positron (4) proton 3. What is the mass number of a carbon atom that contains six protons, eight neutrons, and six electrons? (1) 6 (2) 8 (3) 14 (4) What is the total number of electrons in an atom

6 of potassium? (1) 18 (3) 20 (2) 19 (4) A proton has a charge that is opposite the charge of (1) an alpha particle (3) an electron (2) a neutron (4) a positron 6. The diagram below represents the nucleus of an atom. What are the atomic number and mass number of this atom? (1) The atomic number is 9 and the mass number is 19. (2) The atomic number is 9 and the mass number is 20. (3) The atomic number is 11 and the mass number is 19. (4) The atomic number is 11 and the mass number is Which statement describes the relative energy of the electrons in the shells of a calcium atom? (1) An electron in the first shell has more energy than an electron in the second shell. (2) An electron in the first shell has the same amount of energy as an electron in the second shell. (3) An electron in the third shell has more energy than an electron in the second shell. (4) An electron in the third shell has less energy than an electron in the second shell. 8. According to the electron-cloud model of the atom, an orbital is a (1) circular path traveled by an electron around the nucleus (2) spiral path traveled by an electron toward the nucleus (3) region of the most probable proton location (4) region of the most probable electron location 9. What can be determined if only the atomic number of an atom is known? (1) the total number of neutrons in the atom, only (2) the total number of protons in the atom, only (3) the total number of protons and the total number of neutrons in the atom (4) the total number of protons and the total number of electrons in the atom 10. In the wave-mechanical model, an orbital is a region of space in an atom where there is (1) a high probability of finding an electron (2) a high probability of finding a neutron (3) a circular path in which electrons are found (4) a circular path in which neutrons are found Essential Questions 1. What role have models played in the discovery and interpretation of atomic structure? 2. What are the charges, locations, and masses of the subatomic particles? 3. How do the configurations of subatomic particles affect the properties of an element? 4. How are electron configurations constructed? 5. What is the role of the Mole as a unifying concept of chemistry?

7 PA Standards These are the PA Standards that underlie the Eligible Content in this unit. 3.2.C.A2: 1. Compare the electron configurations for the first twenty elements of the periodic table. 2. Use the mole concept to determine number of particles and molar mass for elements and compounds. 3.2.C.A5: 1. Recognize discoveries from Dalton (atomic theory), Thomson(the electron), Rutherford(the nucleus), and Bohr (planetary model of atom) and understand how each discovery leads to modern theory. 2. Describe Rutherford s gold foil experiment that led to the discovery of the nuclear atom. Identify the major components (protons, neutrons, and electrons) of the nuclear atom and explain how they interact. 3.2.C.A6: 1. Compare and contrast scientific theories. 2. Know that both direct and indirect observations are used by scientists to study the natural world and universe. 3. Identify questions and concepts that guide scientific investigations. 4. Formulate and revise explanations and models using logic and evidence. 5. Recognize and analyze alternative explanations and models. 6. Examine the status of existing theories. 7. Evaluate experimental information for relevance and adherence to science processes. 8. Judge that conclusions are consistent and logical with experimental conditions. 9. Interpret results of experimental research to predict new information, propose additional investigable questions, or advance a solution. 10. Communicate and defend a scientific argument. Common Core Standards for Science and Technical Subjects These are Common Core Standards that are related to the Eligible Content in this unit. CC A: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. CC C: Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text. CC H: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. CC B: Write informative/explanatory texts, including the narration of historical events, scientific procedures/ experiments, or technical processes. CC C: Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience. CC H: Draw evidence from informational texts to support analysis, reflection, and research. Pa core standards for mathematics: CC.2.1HS.F.3: Apply quantitative reasoning to choose and interpret units and scales in formulas, graphs, and data displays. CC.2.1.HS.F.4: Use units as a way to understand problems and to guide the solution of multi-step problems. CC.2.1.HS.F.5: Choose a level of accuracy appropriate to limitations on measurements when reporting quantities. CC.2.2.HS.D.8: Apply inverse operations to solve equations or formulas for a given variable. Next Generation Science Standards These are Next Generation Science Standards that are related to the Eligible Content in this unit. (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. [Clarification Statement: Examples of properties that could be

8 predicted from patterns could include reactivity of metals, types of bonds formed, numbers of bonds formed, and reactions with oxygen.] [Assessment Boundary: Assessment is limited to main group elements. Assessment does not include quantitative understanding of ionization energy beyond relative trends.] DCI: PS1.A: Each atom has a charged substructure consisting of a nucleus, which is made of protons and neutrons, surrounded by electrons. (HS-PS1-7) Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction. [Clarification Statement: Emphasis is on using mathematical ideas to communicate the proportional relationships between masses of atoms in the reactants and the products, and the translation of these relationships to the macroscopic scale using the mole as the conversion from the atomic to the macroscopic scale. Emphasis is on assessing students use of mathematical thinking and not on memorization and rote application of problem-solving techniques.] [Assessment Boundary: Assessment does not include complex chemical reactions.] (HS-PS4-3) Evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model, and that for some situations one model is more useful than the other. [Clarification Statement: Emphasis is on how the experimental evidence supports the claim and how a theory is generally modified in light of new evidence. Examples of a phenomenon could include resonance, interference, diffraction, and photoelectric effect.] [Assessment Boundary: Assessment does not include using quantum theory.] (HS-PS4-4) Evaluate the validity and reliability of claims in published materials of the effects that different frequencies of electromagnetic radiation have when absorbed by matter. [Clarification Statement: Emphasis is on the idea that photons associated with different frequencies of light have different energies, and the damage to living tissue from electromagnetic radiation depends on the energy of the radiation. Examples of published materials could include trade books, magazines, web resources, videos, and other passages that may reflect bias.] [Assessment Boundary: Assessment is limited to qualitative descriptions.