Name:_______________________________________________Date:_______Period:__________
PS#2: Periodic Trends
1. Which of the following is most important in determining the periodic trends across a period? Why?
 Nuclear charge
 Shielding
 Increasing numbers of electrons
 Increasing energy levels
2. Which of the following is (are) important in determining the trend going up or down a group? Why?
 Nuclear charge
 Shielding
 Increasing numbers of electrons
 Increasing energy levels
Atomic and Ionic Radius:
3. Define atomic and ionic radius and give the general trend as you go up the periodic table and across
the periodic table.
4. How are the shielding effect and the size of an atom related?
5. How are the nuclear charge and the size of an atom related?
6. Why is a negatively charged ion larger than its corresponding neutral atom?
7. Which ion is larger, Fe2+ or Fe3+? Explain your choice.
8. For each of the following pairs, circle the atom or ion having the larger radius. Justify your choice.
a)
S or
O
b)
Ca or Ca2+
c)
Na+
or K+
d) Na or K
e)
S2– or
O2–
f)
F or F–
Electronegativity:
9. What is electronegativity?
10. What appears to be the trend in electronegativity as you move from left to right in a row?
11. What appears to be the trend in electronegativity as you move from top to bottom in a column?
12. List the following atoms in order of increasing electronegativity: O, Al, Ca
13. List the following atoms in order of decreasing electronegativity: Cl, K, Cu
Ionization Energy:
14. Define Ionization energy.
15. What happens to the energy needed to remove an electron as the atomic number increases across a
period?
16. What happens to the energy needed to remove an electron as you go down a group?
17. Why does the energy required to remove an electron change as it does?
18. In each of the following pairs, circle the species with the higher ionization energy:
a) Li or Cs
b) Cl or Ar
c) Ca or Br
d) Na or Ne
e) B or Be
19. Summarize the trends you uncovered in the POGIL. For each of the atomic property, draw arrows in
the increasing direction and label which property it is.
11. Use the following element to answer 11(a)-(i)
B
a.
b.
c.
d.
e.
f.
g.
h.
i.
Al
Ga
In
Lowest electronegativity?
Highest ionization energy?
Largest atomic radius?
Which are non-metals?
Which are conductors of electricity?
List them in order from smallest to largest.
Would they gain or lose electrons to form ions?
What charge would the ion have (+ or -)?
Would these be considered cations or anions?
Would the ion be larger or smaller than the atom?
12. Use the following element to answer 12(a)-(k)
Si
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
S
Al
P
Lowest I.E.?
Smallest?
Which are metalloids?
List in order of increasing size (from smallest to largest)
Which are non-metals?
Lowest electronegativity?
Which would rather gain electrons?
Which would rather lose electrons?
Which ones would form cations?
Would these be larger or smaller than the neutral atom?
Which ones would form anions?
Would these be larger or smaller than the neutral atom?