Periodicity Review Worksheet
1. Which atom in the following pairs would have the larger atomic radii?
P or Cl
K or Mg
As or Se
Si or O
P or Ge
Sn or Pb
Cl or Br
Ca or Al
Mg or Ca
Sn or As
Si or S
H or He
Na or Mg
Al or Cl
Sr or Ra
2.Which ion in the following pairs would have the larger radii?
Li+ or Be2+
Cr3+ or Cr6+
S2- or O2-
Mg2+ or Be2+
Na+ or Al3+
I- or Cl-
Cs+ or Be2+
Zn2+ or Fe2+
P3- or S2-
Cu+ or Cu2+
N3- or F-
3.Which member of the following pairs would have a larger radii?
Br or BrCa or Ca2+
S or S6+
Al or Al3+
O or O2Li or Li+
P or P3N3- or Al3+
4.Which atom in the following pairs would have the greater first ionization energy?
Sr or Ba
Cs or Ba
Cl or Ar
In or Sn
Xe or Kr
Mg or Sr
Ca or Cu
5. What is the difference between electron affinity and ionization energy?
6. Which member in the following pairs would have the greater electron affinity &
electronegativity?
F or Cl
S or O
F or O
N or O
F or Any element S or Cl
Nonmetal or Metal
Ca or K
C or O
Ca or F
Mg or Na
Al or Si
Na or K
7. What is the difference between a cation and an anion?
8. Identify three anions in Period 2 that can have the same number of electrons when they
become ions. Do they gain or lose electrons?
9. Identify three cations in Period 3 that can have the same number of electrons when they
become ions. Do they gain or lose electrons?
10. Identify the ions that are most likely to have an ion charge (oxidation state) of 2-? (Hint:
there are five of them)
11. Identify the ions that are most likely to have an ion charge (oxidation state) of 2+? (Hint:
there are six of them)
12. Why do elements in the same family generally have similar properties?
13. Which element has the greatest electron affinity? Why?
14. Which element has the lowest ionization energy? Why?
15. Consider all elements in period 3 for the following (Na through Ar)
____ has the largest atomic radius
____ has the greatest electron affinity
____ has the highest first ionization energy
____ is the most reactive metal
____ is the most reactive non metal
____ is the least reactive
___________ are metalloids
___________ are most likely to be cations
____________are most likely to be anions
_____loses 3 electrons to have noble gas configuration (isoelectronic to the noble gas)
_____ gains 3 electrons to have noble gas configuration (isoelectronic to the noble gas)
16. Consider all elements in group 17 (O through Po)
____ is the least reactive
____ is the most reactive
____ has the greatest electron affinity
____ has the greatest first ionization energy
____ has the smallest atomic radius
17. In a given period, are cations larger or are anions bigger?
18. Is the radius of a cation larger or smaller than the neutral atom? Why?
19. Is the radius of an anion larger or smaller than the neutral atom? Why?