Unit 3 Review Chapters 4 (Atomic Structure) & 6 (Periodic Table) Part 1: Answer the following questions. 1. a. Which scientist created the first modern atomic theory? John Dalton b. What was his theory? 1) All matter is made of extremely small particles called atoms 2) All atoms of a given element are identical. Atoms of a specific element are different from those of any other element 3) Atoms cannot be created, divided into smaller particles, or destroyed 4) Different atoms combine in simple whole number ratios to form compounds 5) In a chemical reaction, atoms are separated, combined or rearranged c. What was his model of the atom called? Billiard Ball d. What was proven wrong and why? All atoms of a given element are identical. Proven wrong b/c of the existence of isotopes. Atoms cannot be divided into smaller particles. Proven wrong b/c of the existence of electrons, protons and neutrons. 2. a. Which scientist did the gold foil experiment? Rutherford b. What did he conclude from the gold foil experiment? Atom is made up of mostly empty space. Atom has a small positive center called the nucleus 3. a. Who discovered the electron? J.J. Thomson b. What was the name of his experiment? Cathode Ray Tube c. What was his model of the atom called? Plum Pudding Model 4. What did Mendeleev do? Arranged the periodic table in order of increasing atomic mass. 5. a. Who arranged the modern periodic table? Moseley b. How is the modern periodic table arranged? In order of increasing atomic number 6. What are the two main parts of the atom? What do they give to the atom? Nucleus which gives mass to the atom and the electron cloud which gives volume to the atom. 7. a. What are the three subatomic particles? Give the symbols of each. Proton, p + Electron, e - Neutron, n o b. What is the charge, mass, and location of each? Proton, positive, 1, nucleus Electron, negative, 0, electron cloud Neutron, neutral, 1, nucleus 8. What is special about the proton? It identifies the atom. 9. Fill in the blanks in the following: a. Mass # = protons + neutrons b. Atomic # = protons = electrons in a neutral atom. 10. What is the difference between Atomic mass and mass #? The atomic mass is found on the periodic table and is the weighted average of the isotopes. The mass number is the mass of one element and must be given or calculated by adding the protons + neutrons.
11. Which of the following are isotopes of the same element? How do you know? 12 a. 5 b. 15 7 c. 12 6 d. 15 5 a and d are isotopes of each other b/c they have the same atomic number (number of protons) but different mass number (different number of neutrons) 12. Calculate the average atomic mass for Boron if it has two naturally occurring isotopes: boron 10 (abundance of 19.8%) and boron 11 (abundance of 80.2%). 13. Identify an element by calculating the average atomic mass. 6 (abundance of 7.5%) and - 7 (abundance 92.5%). Lithium 14. a. Write the isotope notation in two ways (name and symbol) for the two carbon isotopes that have masses of 12 and 14. carbon-14 carbon-12 b. List all that is the same and all that is different between the two carbon isotopes. Same atomic number, number or protons, element Different mass number, number of neutrons 15. What is the maximum number of electrons in the first energy level? 2 What formula is used to determine this? 2n 2 16. Using the following periodic table, label the following: a. Number of Valence Electrons at the top of the groups 1 2 2 2 2 2 2 2 2 2 2 2 3 4 5 6 7 8 b. Identify the following using the numbers from the periodic table. Alkali Metals 1 Noble Gases 5 Alkaline Earth Metals 2 Inner Transition metals 6 Halogens 4 Transition metals 3 c. What is a period on the periodic table? Horizontal row How many periods are there? 7 d. What is a group or family on the periodic table? Vertical column How many groups are there? 18 e. Where are most of the nonmetals located? Right of the stairstep Where are most of the metals located? Left of the stairstep The metalloids are located on either side of the stairstep line except for aluminum.
17. a. Po and Bi are in the same period. b. Po and Te are in the same group. c. Name the metal that is in Group 13 and Period 5. Indium d. Name the nonmetal in Group 16 and Period 2. Oxygen e. Name the metalloid in Group 13 and Period 2 Boron 18. List all the properties of metals? Shiny, lustrous, conductor, malleable, ductile, high melting point and boiling point 19. List all the properties of non-metals? Dull, brittle, non-conductor, low melting point and boiling point 20. List all the properties of metalloids? Semi-conductor 21. List two noble gases. Argon, Krypton, Helium, enon, Neon 22. What is an ion? An atom with a charge 23. a. What is a positive ion called? cation In a positive ion, the number of protons is greater than the number of electrons. 24. What is a negative ion called? anion In a negative ion, the number of protons is less than the number of electrons. 25. Name an element that has similar properties to Carbon. Any element in group 14 26. Name an element that has similar properties to Radium. Any element in group 2 27. What is a Lewis Dot Structure? It s the element symbol surrounded by dots which represent the element s number of valence electrons 28. Draw the Lewis Dot Structure for Carbon, Sodium, Helium, & Neon. 29. What does the Symbol in a Lewis Dot structure represent? The nucleus and the inner electrons 30. What do the dots in a Lewis Dot structure represent? The number of valence electrons 31. What are valence electrons? The electrons in the outermost energy level Part 2: Fill in the blank: Use the words from the word bank below to complete each statement. Energy level Atom Nucleus Atomic mass Atomic number Mass number Electrons Neutrons Electron cloud Isotopes Amu Neutral 32. A(n) atom is the smallest particle of an element that retains properties of that element. 33. All atoms are neutral which means that the number of protons is equal to the number of electrons. 34. The nucleus of an atom contains protons and neutrons.
35. The atomic number is equal to the number of protons in the nucleus of an atom. 36. The number of protons is equal to the number of electrons since an atom has no charge. 37. The mass number is equal to the number of protons and neutrons in the nucleus of an atom and must be given or calculated. 38. The number of neutrons is equal to the mass number minus the atomic number. 39. Isotopes are atoms of the same element with different numbers of neutrons. 40. The atomic mass is equal to the weighted average of the masses of the isotopes and can be found on the periodic table. 41. The electrons are found in the electron cloud. 42. A(n) energy level is a region in the electron cloud where electrons are likely to be found. 43. amu is the unit for atomic mass. Part 3: Fill in the blank: Use the words from the word bank below to complete each statement. Atomic number Periods Groups Alkaline Earth Metals Alkali metals Transition Metals Electron Energy Levels Valence Electrons Halogens Inner Transition Metals 44. Vertical columns of the periodic table are called groups while horizontal rows are periods. 45. The alkali metals are elements in Group 1A that react violently with water. 46. The alkaline earth metals are elements in Group 2A. 47. The halogens is the name of the family of nonmetals that includes fluorine and chlorine. 48. The transition metals are the Group B elements that are located in groups 3 through 12. 49. The inner transition metals are made up of the Lanthanides and the Actinides. 50. The subatomic particle that is important in determining the chemical properties of the element is the electron 51. The period number corresponds to the number of energy levels. 52. The group number corresponds to the number of valence electrons. Part 4: Answer the following questions. 53. Complete the element symbol, give the proper name and complete the numbers below. Element Symbol Name Atomic Number Mass Number # Protons # Electrons # Neutrons Oxygen-18 8 18 8 8 10 +2 Calcium-40 Ion + Sodium-24 Ion 20 40 20 18 20 11 24 11 10 13
54. Which of the following are isotopes of the same element? Circle them. 5025 A 5010 A 5525 A 45 55. For the isotopes list the protons, neutrons, and electrons. Protons Electrons Neutrons Name of isotope 14 7 N 7 7 7 nitrogen-14 15 7 N 7 7 8 nitrogen-15 56. Calculate the average atomic mass for the element if it has 3 isotopes. Isotope 50 53 51 % Abundance 20% 50% 30% 2 A 57. What element is the standard for the atomic mass unit? Carbon 58. Elements in the same group have the same number of valence electrons. 59. How many valence electrons does Helium have? 2