Name: _____________________________
Per:______
Date:__________
WS 6-2: Trends in the Periodic Table
Use the periodic table to decide which atom in
each pair has the larger atomic radius?
Use the periodic table to decide which atom or
ion has the larger ionization energy?
_____ 1. Li or K
_____ 15. Na or O
_____ 2. Ca or Ni
_____ 16. Be or Ba
_____ 3. Ga or B
_____ 17. Ar or F
_____ 4. O or C
_____ 18. Cu or Ra
_____ 5. Cl or Br
_____ 19. I or Ne
_____ 6. Be or Ba
_____ 20. K or V
_____ 7. Si or S
_____ 21. Ca or Fr
_____ 8. Fe or Au
_____ 22. W or Se
Use the periodic table to decide which ion has
the smaller atomic radius?
Write the charge that each atom will acquire
when it has a complete set of valence electrons.
_____ 9. K+ or O2-
_____ 23. O
_____ 10. Ba2+ or I-
_____ 24. Na
_____ 11. Al3+ or P3-
_____ 25. F
_____ 12. K+ or Cs+
_____ 26. N
_____ 13. Fe2+ or Fe3+
_____ 27. Ca
_____ 14. F- or S2-
_____ 28. Ar
29. Define atomic radius: ________________________________________________________________
_______________________________________________________________________________
30. Why do atoms get smaller as you move across a period? ____________________________________
_______________________________________________________________________________
31. Explain the relationship between the relative size of an ion to its atom and the charge on the ion.
_______________________________________________________________________________
_______________________________________________________________________________
32. Explain why noble gases are inert and do not form ions. ____________________________________
_______________________________________________________________________________
WS 6-2 : Trends in the Periodic Table
Page 1 of 5
A) Atomic Radius
33. Atomic radius is measured in a unit called angstroms, Å. Define atomic radius.
_________________________________________________________________________________
_________________________________________________________________________________
34. The atomic radii of the elements from Group 1 are Li, 1.52 Å; Na, 1.86 Å; K, 2.27 Å;
Rb, 2.48 Å; Cs, 2.66 Å. Plot these radii on the graph below.
Atomic Radius (Å)
3.0
2.0
1.0
Li
Na
K
Rb
Cs
Group 1 (IA) Elements (Increasing Atomic Number →)
35. Trend: Down a group, as atomic number increases, atomic radius ____________________.
36. Explain the trend:
_________________________________________________________________________________
_________________________________________________________________________________
37. The atomic radii of the elements from Period 3 are Na, 1.86 Å; Mg, 1.60 Å; Al, 1.43 Å;
Si, 1.17 Å; P, 1.10 Å; S, 1.04 Å; Cl, 0.99 Å. Plot these radii on the graph below.
Atomic Radius (Å)
2.0
1.5
1.0
0.5
Na
Mg
Al
Si
P
S
Cl
Period 3 Elements (Increasing Atomic Number →)
38. Trend: Across a period, as atomic number increases, atomic radius_____________________.
WS 6-2 : Trends in the Periodic Table
Page 2 of 5
39. Explain this trend:
_________________________________________________________________________________
_________________________________________________________________________________
B) Ionization Energy
40. Define first ionization energy.
_________________________________________________________________________________
_________________________________________________________________________________
41. What are second, third, and other successive ionization energies?
_________________________________________________________________________________
_________________________________________________________________________________
First Ionization Energy (kJ/mol)
42. The first ionization energies for the elements in Group 2 are Be, 900 kJ/mol; Mg, 738 kJ/mol; Ca,
590 kJ/mol; Sr, 550 kJ/mol; Ba, 503 kJ/mol. Plot these energies on the graph below.
1000
750
500
Be
Mg
Ca
Sr
Ba
Group 2 (IIA) Elements (Increasing Atomic Number →)
43. Trend: Down a group, as atomic number increases, 1st ionization energy ________________.
44. Explain this trend:
_________________________________________________________________________________
_________________________________________________________________________________
WS 6-2 : Trends in the Periodic Table
Page 3 of 5
First Ionization Energy (kJ/mol)
45. The first ionization energies for the elements in Period 2 are Li, 520 kJ/mol; Be, 900 kJ/mol;
B, 801 kJ/mol; C, 1087 kJ/mol; N, 1402 kJ/mol; O, 1314 kJ/mol; F, 1681 kJ/mol.
Plot these energies on the graph below.
1500
1000
500
Li
Be
B
C
N
O
F
Period 3 Elements (Increasing Atomic Number →)
46. Trend: Across a period, as atomic number increases, 1st ionization energy _______________.
47. Explain this trend and any irregularities:
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
C) Electronegativity
48. Define electronegativity.
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
WS 6-2 : Trends in the Periodic Table
Page 4 of 5
49. The electronegativity values for elements in Group 2 are Be 1.50; Mg, 1.29; Ca, 1.02; Sr, 0.97; Ba,
0.93. Plot these electronegativities on the graph below.
Electronegativity
1.50
1.25
1.00
Be
Mg
Ca
Sr
Ba
Group 2 (IIA) Elements (Increasing Atomic Number →)
50. Trend: Down a group, as atomic number increases, electronegativity___________________.
51. Explain this trend:
_________________________________________________________________________________
_________________________________________________________________________________
52. The electronegativity values for elements in Period 2 are Li, 0.96; Be, 1.50; B, 2.02; C, 2.56;
2.81; O, 3.37; F, 4.00. Plot these electronegativities on the graph below.
N,
Electronegativity
4.0
3.0
2.0
1.0
Li
Be
B
C
N
O
F
Period 2 Elements (Increasing Atomic Number →)
53. Trend: Across a period, as atomic number increases, electronegativity___________________.
54. Explain this trend:
_________________________________________________________________________________
_________________________________________________________________________________
WS 6-2 : Trends in the Periodic Table
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