6.3 Study Guide. Name: Class: Date: True/False Indicate whether the statement is true or false.

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1 Name: Class: Date: ID: A 6.3 Study Guide True/False Indicate whether the statement is true or false. 1. Elements in the same family tend to have the same number of valence electrons. 2. The radius of an atom is defined as half the distance between the nuclei of two adjacent or bonded atoms of that element. 3. The octet rule states that atoms will gain, lose, or share electrons to achieve a complete set of eight valence electrons. 4. When an atom loses electrons, its radius gets smaller. 5. The electronegativity of elements increases from left to right and from top to bottom on the periodic table. 6. An atom that gains an electron will form a positive ion. 7. The same amount of energy is required to remove each electron sequentially from an atom. Multiple Choice Identify the choice that best completes the statement or answers the question. 8. Which region is referred to as the p-block on the diagram? a. A c. C b. B d. D 9. Which region is referred to as the f-block on the diagram? a. A c. C b. B d. D 1

2 Name: ID: A 10. Which region contains elements with two valence electrons? a. A c. C b. B d. D 11. Which diagram correctly depicts the trend in electronegativity? a. a c. c b. b d. d 12. Which diagram correctly depicts the general trend in first ionization energy? a. a c. c b. b d. d 13. Which is defined as the energy required to remove an electron from an atom of an element in the gaseous state? a. ionization energy c. ionic radius b. electronegativity d. law of octets 14. In which pair is the one on the left larger than the one on the right? a. Na, Rb c. Br, Brb. S, Mg d. K, K+ 15. Which correctly describes elements in the same group? a. They have the same number of valence electrons. b. They have electrons in the same outermost energy level. c. They have the same atomic radius. d. They must be in the same state of matter. 2

3 Name: ID: A 16. Which is the most important characteristic in detemining an element s chemical properties? a. the number of protons and neutrons in its nucleus b. which period it is found in c. the number of valence electrons it contains d. its outermost energy level 17. Which property describes how much energy must be added to an atom to remove an outermost electron? a. atomic radius c. electronegativity b. ionic radius d. ionization energy Short Answer 18. Label the blank periodic table with the following terms. A: metalloids B: element with the highest electronegativity C: alkali metals D: lanthanide series E: element with the greatest atomic radius F: noble gases G: halogens 19. Explain the significance of the stair-step line located near the right-hand side of the periodic table 20. Do the figures in this partial periodic table demonstrate the trend in atomic radius, ionic radius, or neither of these? Relate your answer to the structure of atoms across the periodic table. 3

4 Name: ID: A 21. Place these five elements in order of electronegativity, with the highest electronegativity first. 22. The second ionization energy of sodium is very high as compared to the first ionization energy. Explain this trend of sodium. 23. Why is the size of a sodium ion (Na + ) less than that of a sodium atom (Na)? 24. Define ionization energy. Essay 25. When atoms form ions, their radius generally changes. Describe the change in radius when positive and negative ions are formed. Relate this change to the change in electron number and/or arrangement. Problem 26. Identify the element having the largest size and the element having the highest electronegativity from the list of electron configurations given below: a. [Ne] 3s 2 3p 3 b. [Ne] 3s 2 3p 4 c. [Ne] 3s 2 3p 5 d. [Ne] 3s 2 3p 3 4s 2 3d Arrange the elements given below in the increasing order of their atomic size. Element A 1s 2 2s 2 2p 6 Element B 1s 2 2s 2 Element C 1s 2 2s 2 2p 6 3s 1 Element D 1s 2 2s 2 2p 3 4

5 ID: A 6.3 Study Guide Answer Section TRUE/FALSE 1. ANS: T PTS: 1 DIF: Bloom's Level 2 2. ANS: T PTS: 1 DIF: Bloom's Level 2 NAT: B.1 3. ANS: T PTS: 1 DIF: Bloom's Level 1 NAT: B.1 4. ANS: T PTS: 1 DIF: Bloom's Level 1 NAT: B.1 5. ANS: F PTS: 1 DIF: Bloom's Level 2 6. ANS: F PTS: 1 DIF: Bloom's Level 2 NAT: B.1 7. ANS: F PTS: 1 DIF: Bloom's Level 2 NAT: B.1 B.6 MULTIPLE CHOICE 8. ANS: D PTS: 1 DIF: Bloom's Level 2 NAT: UCP.2 9. ANS: B PTS: 1 DIF: Bloom's Level 2 NAT: UCP ANS: A PTS: 1 DIF: Bloom's Level 4 NAT: UCP.2 B.1 B ANS: B PTS: 1 DIF: Bloom's Level 4 NAT: UCP.2 B ANS: B PTS: 1 DIF: Bloom's Level 4 NAT: UCP ANS: A PTS: 1 DIF: Bloom's Level 1 NAT: UCP ANS: D PTS: 1 DIF: Bloom's Level 3 NAT: B.1 B ANS: A PTS: 1 DIF: Bloom's Level ANS: C PTS: 1 DIF: Bloom's Level ANS: D PTS: 1 DIF: Bloom's Level 1 1

6 ID: A SHORT ANSWER 18. ANS: PTS: 1 DIF: Bloom's Level 1 NAT: UCP.2 B ANS: The stairstep line separates the metals from the nonmetals on the periodic table. Elements that are adjacent to this line are considered metalloids and have some properties of metals and some properties of nonmetals. PTS: 1 DIF: Bloom's Level 3 NAT: UCP.2 B ANS: These show the atomic radius change. As electrons are added to the outer energy levels of an atom (as one moves across the periodic table), the size of the atom decreases. This is because the additional positive charge in the nucleus attracts the electrons more strongly and no additional shielding effect occurs across the period. PTS: 1 DIF: Bloom's Level 4 NAT: UCP.2 B.1 B ANS: B, D, C, E, A PTS: 1 DIF: Bloom's Level 4 NAT: UCP.2 B ANS: Ionization is related to the number of valence electrons in an atom. Sodium has one valence electron. It forms a common sodium 1+ ion, but is unlikely to form a sodium 2+ ion. The jump in ionization energy shows that atoms hold onto their inner core electrons more strongly than they hold onto their valence electrons. PTS: 1 DIF: 1 REF: Page 167 Page 168 OBJ: Relate period and group trends in atomic radii to electron configuration. NAT: UCP.1 B.1 B.2 TOP: Relate period and group trends in atomic radii to electron configuration. KEY: Ionization energy MSC: 2 2

7 ID: A 23. ANS: The loss of an electron from a sodium atom results in a smaller radius. The electrostatic repulsion between the remaining number of electrons decreases thus allowing them to be pulled closer to the nucleus. Therefore, the size of a sodium ion (Na + ) is less than that of a sodium atom (Na). PTS: 1 DIF: 2 REF: Page 165 OBJ: Relate period and group trends in atomic radii to electron configuration. NAT: UCP.1 B.1 B.2 TOP: Relate period and group trends in atomic radii to electron configuration. KEY: Atomic size Ionic radius MSC: ANS: Ionization energy of an atom is defined as the energy required to remove an electron from a gaseous atom. PTS: 1 DIF: 1 REF: Page 167 OBJ: Compare period and group trends of several properties. NAT: UCP.1 B.2 TOP: Compare period and group trends of several properties. KEY: Ionization energy MSC: 1 ESSAY 25. ANS: When positive ions form, they tend to have a smaller radius than their parent neutral atom. This is because electrons are being lost from the outer energy level, which causes less electron repulsion so that the electrons can move in closer to the positively charged nucleus. Negative ions tend to get larger because additional electrons are added, sometimes adding another energy level to the outside of the atom. Additionally, the repulsion between the electrons in the outer energy level will increase with the added electron, causing all of the valence electrons to move apart thereby increasing the radius of the negative ion. PTS: 1 DIF: Bloom's Level 5 NAT: B.1 PROBLEM 26. ANS: The element having the largest size has an electron configuration of [Ne] 3s 2 3p 3 4s 2 3d 3. The element having the highest electronegativity has an electron configuration of [Ne] 3s 2 3p 5. PTS: 1 DIF: 2 REF: Page 163 Page 168 OBJ: Relate period and group trends in atomic radii to electron configuration. NAT: UCP.1 B.1 B.2 TOP: Relate period and group trends in atomic radii to electron configuration. KEY: Electron configuration Atomic size Electronegativity MSC: 2 NOT: The size of the atom depends on the number of shells in an atom. Electronegativity increases across a period. 3

8 ID: A 27. ANS: The arrangement of elements in the increasing order of their atomic size is B < A < D < C. Element B is the smallest and Element C is the largest. PTS: 1 DIF: 1 REF: Page 163 OBJ: Relate period and group trends in atomic radii to electron configuration. NAT: UCP.1 B.1 B.2 TOP: Relate period and group trends in atomic radii to electron configuration. KEY: Atomic size Electron configuration MSC: 2 NOT: The size of an atom depends upon the number of shells in an atom. In the same period, the atomic size decreases from left to right. 4