Atomic Structure Chapter 4 Mr. Hines

Transcription

1 Atomic Structure Chapter 4 Mr. Hines Part A Standard model of the atom Learning Targets and I can statements 1 List, label, and describe the parts of an atom. 2 Identify the atomic number and the atomic mass of all elements and explain what they mean. 3 Describe atoms using the classical model. 4 Describe atoms using the Marble in the football stadium model. I CAN Part B Electrons and the Periodic Table 5 Define energy levels and explain how electrons are organized into energy levels. 6 Determine how many electrons can be held in each energy level. 7 Explain how electrons fill energy levels (aufbau principle). 8 Draw atomic models with proper amounts of subatomic particles. 9 Define valence electrons and determine the amount for each element. 10 Identify groups on the periodic table and explain the relationship between valence electrons and groups. 11 Determine the amount of energy levels for each element. 12 Identify periods on the periodic table and explain the relationship between energy levels and periods. 13 Compare and contrast the various elements on the periodic table. Part C The Octet Rule 14 Identify the various families on the periodic table and describe their properties. 15 Interpret the octet rule 16 Define Lewis dot structure and be able to write them. 17 Explain the easiest path for an atom to achieve an octet and give examples. Part D - Isotopes 18 Define isotopes and write proper isotope notation. 19 Determine the number of all subatomic particles of an element when given the atomic mass of an isotope. 20 Compare and contrast isotopes of the same element. 21 Convert a percent to a decimal. 22 Calculate the atomic mass of each element from known scientific data. 23 Explain why the atomic mass of most elements is written as a decimal. 24 Name and draw the isotopes of Hydrogen. 25 Evaluate the placement of hydrogen and helium on the periodic table. Matter Atoms Protons Neutrons Electrons Amu Exist Atomic Subatomic Negative Positive Atomic Atomic Periodic Table mass units particles charge charge number mass Neutral charge Electron cloud Energy Level Vertical column Horizontal row Lewis dot structure Natural percent abundance Nucleus Bike symbol Space Model Volume Valence Electron Mass Period Group Abundance Big Mac Percent Aufbau principle Isotope Average Hydrogen Decimal Deuterium Tritium Easiest path family Noble gas stable Octet rule Chemistry Bond oct

2 PART A STANDARD MODEL OF THE ATOM Target 1 List, label, and describe the parts of an atom. A. Remember from earlier that matter is anything made of. B. Atoms are the basic building blocks of all matter. C. Atoms are made of smaller particles. These are listed below. 1. Protons (+) and found in nucleus (center) of atom. 2. Neutrons neutral or zero charge (0) and found in of atom. Collectively, protons and neutrons are referred to as atomic mass units (amu) term meaning that they are found in the nucleus. 3. Electrons (-) and found moving around the nucleus of an atom. Electrons have such a small mass that we don t even consider them when measuring mass.. Questions 1. List the parts of an atom. (3 parts) a. b. c. 2. Describe where the parts of an atom are located. a. b. c. 3. Indicate the charge on each part of the atom. a. b. c. Target 2 - Identify the atomic number and the atomic mass of all elements and explain what they mean. A. All of the elements are listed on the of Elements. B. Elements are different kinds of atoms with a name, symbol, and unique properties. C. The Periodic Table lists the elements in the order based on the number of. D. The atomic number is written the symbol and tells you the number of protons. E. The number of protons identifies each individual element. F. The atomic number will also tell you the number of electrons.* G. The atomic mass is written the symbol and tells you the total number of protons and neutrons. H. If you want to know the number of neutrons, you can subtract the atomic number from the atomic mass. I. Protons, neutrons, and electrons are collectively referred to as. J. Subatomic particles found in the nucleus (protons and neutrons) are more specifically called atomic mass units. K. Atomic mass units are abbreviated as.

3 Notes 12 Mg Questions 1. What is listed on the periodic table? 2. What is the difference between an element and an atom? 3. What determines the order in which elements are listed on the periodic table? 4. Where is the atomic number listed on the periodic table? 5. Where is the atomic mass listed on the periodic table? 6. What does the atomic number tell you about an element? 7. What does the atomic mass tell you about an element? 8. How do you determine the amount of neutrons in an element? 9. How many protons does Potassium have? 10. How many neutrons does Potassium have? 11. How many electrons does Potassium have? 12 How many subatomic particles does Potassium have? 13. How many atomic mass units does Potassium have? Target 3 Describe atoms using the classical model - Pg 129 A. The classical model of the atom. 1. Protons and neutrons are particles located in the. 2. Electrons move around the nucleus. 3. It is known that electrons occupy a very large amount of space around the nucleus 4. Since the electrons occupy a large space around the nucleus, we call that space the. 5. The electron cloud simply refers to the space where the electrons exist. 6. Label the electron cloud on the next illustration.

4 Target 4 - Explain the Marble in the football stadium model of an atom A. The classical model of the electron is commonly used around the world, but is. B. A more accurate model of the atom is known as the marble in the football stadium. 1. If an atom were the size of a football stadium, the nucleus would be about the size of a. 2. Therefore, the electrons pretty much occupy all of the space in the stadium. 3. In other words, atoms are 99.99%! 4. Draw a marble in the center this stadium. PART B ELECTRONS AND THE PERIODIC TABLE Target 5 Define energy levels and explain how electrons are organized into energy levels 1. Energy Level - Specific around the nucleus where electrons exist 2. Electrons are well organized in the electron cloud into energy levels 3. can be visualized similar to planets orbiting around the sun each planet is further away from the sun and do not leave their orbits Solar system with planets revolving around sun Atom with electrons revolving around the nucleus 4. Energy levels around the nucleus are sort of like layers of an. 5. Energy levels can also be compared to rungs on a ladder if you climb a ladder, your feet will be on the rungs of the ladder. 6. There are a total of energy levels.

5 Target 6 - Determine how many electrons can be held in each energy level. A. Energy levels can only hold so many electrons Energy level Amount of electrons held Notes box (drawing) Questions 1. What particles are found in the nucleus of an atom? 2. Where are the electrons of an atom? 3. Explain the marble in the stadium model of the atom. 4. What is meant by the electron cloud? 5. What is an energy level of the electron cloud? 6. How many electrons can be held in the 1 st energy level? 7. How many electrons can be held in the 2 nd energy level? 8. How many electrons can be held in the 3 rd energy level? 9. How many electrons can be held in the 5 th energy level? Target 7 - Explain how electrons fill energy levels A. Electrons will fill the energy levels first (aufbau principle). B. When the innermost energy levels are filled, electrons must fill energy levels. C. This is similar to people filling around a boxing match once the front rows are filled, outer seating will fill up. D. For example Lithium has 3 electrons. 1. The first 2 electrons will fill the first energy level 2. The third electron will therefore be forced to exist in the second energy level. E. This concept is best learned through drawings. Target 8 - Draw atomic models with proper amounts of subatomic particles. Table Z Hydrogen Helium Lithium

6 Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminum

7 Silicon Phosphorus Sulfur Chlorine Argon Potassium Target 9 - Define valence electrons and determine the amount for each element. A. Valence electrons electrons that are located in the B. From the drawings on Table Z, determine the amount of valence electrons for each element. 1. Hydrogen = 2. Helium = 3. Lithium = 4. Beryllium = 5. Boron = 6. Carbon = 7. Nitrogen = 8. Oxygen = 9. Fluorine = 10. Neon = 11. Sodium = 12. Magnesium = 13. Aluminum = 14. Silicon = 15. Phosphorus = 16. Sulfur = 17. Chlorine = 18. Argon = Einstein moment - can you explain the arrangement of the elements on the periodic table based on valence electrons?

8 Target 10 - Identify groups on the periodic table and explain the relationship between valence electrons and groups. (Pg 118) 1. Groups on the periodic table are columns - draw a vertical line over here 2. For example, Sodium, Lithium and Hydrogen are all in the same (group 1) 3. Groups on the periodic table are divided into 2 catagories. a. Group A b. Group B 4. In this chemistry class, we will mostly speak of. (Group B for advanced studies) 5. Label the groups on your periodic table as demonstrated in class Target 11 Determine the amount of energy levels for each element. A. From the drawings on Table Z, determine the amount of energy levels for each element. 1. Hydrogen = 11. Sodium = 2. Helium = 12. Magnesium = 3. Lithium = 13. Aluminum = 4. Beryllium = 14. Silicon = 5. Boron = 15. Phosphorus = 6. Carbon = 16. Sulfur = 7. Nitrogen = 17. Chlorine = 8. Oxygen = 18. Argon = 9. Fluorine = 10. Neon = Einstein moment - can you explain the arrangement of the elements on the periodic table based on energy levels? Target 12 - Identify periods on the periodic table and explain the relationship between energy levels and periods. (Pg 118) 1. on the periodic table are horizontal columns (draw a horizontal line here) 2. For example, sodium, magnesium, and aluminum are all in the same (period 3). 3. This means that elements in period 3 will all have energy levels 4. Label the periods on your periodic table as demonstrated in class

9 Number each group and period on the periodic table as demonstrated in class. Practice Indicate which GROUP each element is in. Element Group Element Group Element Group Element Group Mg B C O Ca Al Si S Sr Ga Ge Se Practice Indicate which PERIOD each element is in. Element Period Element Period Element Period Element Period Li B N Ne Na Al P Ar Ca Fe Cu As 1. What is a group on the periodic table? 2. What is a period on the periodic table? Target 13 - Compare and contrast the various elements on the periodic table. Venn PART C THE OCTET RULE Target 14 - Identify the various families on the periodic table and describe their properties Go to the periodic table of families. Target 15 - Interpret the octet rule A. Noble gases Family of elements on the periodic table in. B. The noble gases all have their outermost energy levels filled with electrons. C. When an atom s outermost energy level is filled, it is called. D. Stable is a condition where change is not likely. E. All of the elements on the periodic table will try to become stable like the. F. In other words, the other elements will try to get 8 electrons in their outermost energy level. G. It can also be phrased that elements will try to get 8 valence electrons. H. In order to achieve this, elements will electrons from other atoms. I. This is known as the OCTET RULE. J. atoms will gain or lose electrons in order to obtain the electron structure of a noble gas usually eight electrons (oct=8)

10 Questions 1. What is meant by the term stable? 2. What is something in your life that is stable? 3. What is meant by the term unstable? 4. What is something in your life that is unstable? 5. How many electrons on the outermost energy level will create a stable atom? 6. How many valence electrons will create a stable atom? 7. What will atoms do to get 8 valence electrons? 8. What is the octet rule? 9. What number does oct represent? Target 16 Define Lewis dot structure and be able to write them. A. Lewis Dot Structure Abbreviated diagram of an atom showing only the B. Why write Lewis dot structures? A large part of chemistry involves the understanding of how atoms bond together valence electrons - alone - are responsible for bonding. Writing Lewis dot structures is a to drawing atoms and their electrons C. Lewis dot structures are best learned by doing them. Draw a Lewis Dot Structure for the following Elements. H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

11 Target 17 Explain the easiest path for an atom to achieve an octet and give examples. A. If you were given the choice of using a pair of scissors or a to cut the grass in your yard, which would you choose and why? B. To achieve an octet, elements will naturally choose the. C. Example 1: Chlorine has 7 valence electrons. It is easier for Chlorine to gain 1 electron to achieve an octet rather than lose 7. D. Example 2: Magnesium has 2 valence electrons. It is easier for Magnesium to lose its 2 valence electrons to achieve an octet than to gain 6. Notes Symbol Element Valence electrons O Gain or Lose How many? Noble gas Lewis structure P Ca Na Al F K N Sr Questions 1. What family on the periodic table does every element want to be like? 2. In terms of electrons, what is meant by the easiest path? 3. Why does Aluminum lose 3 electrons instead of gaining 5? 4. Why does Phosphorus gain 3 electrons instead of losing 5? 5. What is the octet rule? 6. What is special about the Noble gas family?

12 PART D - ISOTOPES Target 18 - Define isotope and write proper isotope notation A. Even though atoms are considered to be the same based on the amount of, they can have different amounts of. B. In nature, elements will contain different amounts of neutrons. C. Isotope - elements that have different numbers of D. If most elements have a different number of neutrons, how can the atomic mass number be determined? E. Whenever an Isotope is written, it includes the atomic mass of the isotope after the symbol separated by a dash. Practice Write the proper isotope notation for each example Helium Carbon Helium Carbon Nitrogen Nitrogen Target 19 - Determine the number of all subatomic particles of an element when given the atomic mass of an isotope Oxygen 17 Phosphorus - 33 Fluorine - 21 Copper - 66 Calcium - 42 Potassium - 41

13 Target 20 Compare and contrast isotopes of the same element. Target 21 - Convert a percent to a decimal. A. A percent can be written as a decimal by moving the decimal point to the left 2 places. notes Percent Decimal Percent Decimal Percent Decimal 27% 976% 4% 1.2% %.56% Target 22 - Calculate the atomic mass of each element from known scientific data A. Why is the atomic mass for each element written as decimal? B. Even though atoms are considered to be the same based on the amount of protons, they can have different amounts of neutrons. 1. For example, a neon atom will always have 10 protons. However, neon atoms can have different amounts of neutrons. 2. Because of this, neon atoms will have different atomic masses. C. The atomic mass number is calculated by the AVERAGE of its abundance in nature. D. In order to do this, you must know 3 things 1. The number isotopes of the element 2. The mass of each isotope 3. The natural percent abundance of each isotope. Carbon 1. The number of stable isotopes of the element 2. The mass of each isotope 3. The natural percent abundance of each isotope. C-12 C-13 notes % 1.11% The average mass reflects both the mass and the relative abundance of the isotopes as they occur in nature

14 Calculate the average atomic mass for each element Natural Percent Abundance of Stable Isotopes of Some Elements Name Notation Natural percent abundance Mass (amu) Average atomic mass Hydrogen H % H % H % Helium He % He % Nitrogen N-14 N % % Target 23 Explain why the atomic mass of most elements is written as a decimal. notes

15 Target 24 - Name and draw the isotopes of Hydrogen notes Target 25 - Evaluate the placement of helium on the periodic table Notes