Chemistry Unit 3 – Periodic Trends

Name……………………………………...…….. Hour………...

Directions: Complete the following statement with the appropriate word or phrase. 1. The vertical columns on the Periodic Table are called ___families/groups___. 2. The elements of the ___Noble gas___ family include helium, argon and xenon. 3. The horizontal rows on the Periodic Table are called ___periods___. 4. The distance from the nucleus of an atom to its valence electron is called atomic ___radius___. 5. The energy required to remove a valence electron from an atom is called ___ionization___ energy. 6. The elements of the ___alkali metal___ family include sodium, potassium and strontium. 7. A measure of the atom’s nucleus to attract electrons from a different atom within a covalent bond (a bond between non-metal atoms) is called ___electronegativity___. 8. Non-valence electrons that shield valence electrons from the Coulombic attractions from the protons in the nucleus are called ___shielding electrons___. 9. The elements of the ___halogen___ family include fluorine, bromine and iodine. 10. The Coulombic attractions that a valence electron actually experiences is called ___effective nuclear charge___ and is calculated by determining the difference in nuclear charge to shielding electrons. 11. The elements of the ___alkaline earth__ family include barium, calcium and magnesium. 12. Elements classified as metals tend to (gain, lose) ___lose___ electrons while elements classified as non-metals tend to (gain, lose) ___gain___ electrons. Directions: Select the letter that best completes the statement or answers the question. 13. ___C___ In explaining periodic trends in a period, which statement is false? a. Effective nuclear charge increases. c. Energy levels increase. b. Atomic radius decreases. d. Nuclear charge increases. 14. ___A___ In explaining periodic trends in a family, which statement is false? a. Effective nuclear charge increases. c. Energy levels increase. b. Atomic radius increases. d. Nuclear charge increases. 15. ___C___ Which atom below has the largest nuclear charge, Z? a. Be b. Si c. Rb Page 1 of 4

d. C

16. ___C___ Which atom below has the most shielding electrons? a. Mg b. F c. K

d. Be

17. ___A___ Which atom below has the same number of shielding electrons as phosphorous? a. Silicon b. Nitrogen c. Calcium d. Lithium 18. ___B___ Which atom below has the largest effective nuclear charge, Z*? a. Calcium b. Sulfur c. Sodium d. Carbon 19. ___A___ Which atom below has an effective nuclear charge of +3? a. Al b. Ne c. Na d. Cl 20. ___A___ Which atom below has exactly two shielding electrons? a. Fluorine b. Aluminum c. Calcium d. Helium 21. ___C___ Which atom below has the smallest effective nuclear charge, Z*? a. Oxygen b. Chlorine c. Sodium d. Argon 22. ___B___ Which atom below has the same number of valence electrons as oxygen? a. Aluminum b. Sulfur c. Fluorine d. Magnesium 23. ___C___ Which atom below has the largest electronegativity? a. Na b. P c. Cl

d. Br

24. ___C___ Which atom below has the largest atomic radius? a. S b. B c. Se

d. Br

25. ___B___ Of the elements listed, which has the highest first ionization energy? a. Li b. Be c. Na d. Mg 26. ___B___ Properties of the alkaline earth metals that increase from Be to Ba include which of the following? i. Atomic radius ii. Ionization energy iii. Nuclear charge a. i and ii only b. i and iii only c. ii and iii only d. i, ii and iii 27. ___B___The removal of a valence electron from which gaseous atom requires the greatest amount of energy? a. Na b. Cl c. K d. Br 28. ___C___ Which equation represents the first ionization of calcium? a. Ca(s)  Ca+(g) + ec. Ca(g)  Ca+(g) + eb. Ca+(g)  Ca2+(g) + ed. Ca2+(g) + e-  Ca+(g)

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29. ___B___ Which element below has the largest atomic radius? a. Br b. K c. Mg

d. Na

30. ___B___ Which pair of symbols identifies two elements that are metals? a. O and N b. Ti and Ca c. Si and Ge d. He and Ne 31. ___C___ Electronegativities change both down a group and across a period. In general these changes are to:

a. b. c. d.

Down a group Increase Increase Decrease Decrease

Across a period from left to right Increase Decrease Increase Decrease

32. ___C___ When the atoms: Ba, Cs, Mg, Na are arranged in order of increasing size, what is the correct order? a. Cs < Na < Mg < Ba c. Mg < Na < Ba < Cs b. Mg < Ba < Na < Cs d. Ba < Mg < Na < Cs 33. ___D___ In the periodic table, as the atomic number increases from 11 to 17, what happens to the atomic radius? a. It remains constant. c. It increases only b. It increases, then decrease. d. It decreases only. 34. ___D___ Which of the following properties generally decreases across the periodic table from sodium to chlorine? a. First ionization energy c. Atomic mass b. Electronegativity d. Atomic radius 35. ___A___ Which pair of symbols identifies two elements that are metalloids? a. B and Ge b. Mg and Si c. P and As d. Ti and V 36. ___C___ Nitrogen has a greater first ionization energy than oxygen. What is the best explanation for this observation? a. Nitrogen is more electronegative than oxygen. b. A nitrogen atom is smaller than an oxygen atom. c. The electron ionized from nitrogen experiences less electron-electron repulsion than the electron ionized from oxygen. d. The electron ionized from nitrogen is a 2s electron, while the electron ionized from oxygen is a 2p electron. 37. ___A___ Which element has chemical properties most similar to those of P? a. N b. Al c. S d. Ar Page 3 of 4

38. ___C___ Which pair of symbols identifies two elements that are non-metals? a. Ni and Cu b. Sr and Cr c. P and O d. B and Si Directions: For each of the following pairs, circle the atom that correctly answers the question. The atom with the largest first ionization energy. 39. O or Ne

40. Mg or K

41. K or Cl

42. Si or F

The atom with the larger effective nuclear charge. 43. Mg or Cl

44. S or F

45. N or Be

46. Cl or Al

49. Ne or Si

50. P or O

The atom with the smaller atomic radius. 47. C or Al

48. Mg or K

The atom with the smaller electronegativity. 51. F or C

52. C or Si

53. Li or Na

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