Untitled - Kelly Walsh High School

126 CHEMISTRY FOR THE UTTERLY CONFUSED
ANSWER KEY
1. The effective nuclear charge is the nuclear charge minus the screening effect
of the core electrons.
2. Columns on the periodic table are groups or families.
3. The effective nuclear charge increases towards the right in any period of the
periodic table.
4. F 5. T 6. c
7. The increase in the effective nuclear charge towards the right of a period
causes the ionization energy to increase towards the right.
8. The atomic radius increases towards the bottom of any family. This increase
in radius leads to a decrease in the ionization energy towards the bottom of
the family.
9. Mg, P, and Ar 10. K + is smaller than K 11. T 12. a
13. The increase in the effective nuclear charge towards the right of a period
causes the electron affinities to increase towards the right, except for the
noble gases.
14. The atomic radius increases towards the bottom of any family; this increase
in radius leads to a decrease in the electron affinity towards the bottom of
the family.
15. Cl is larger than Cl
16. K < Br < Ar
17. Ar < K < Br
18. Mg 2 < Na < Ne < F < O 2
19. The energy necessary will be the sum of the first, second, and third ionization
energies.
20. It is an exception because moving an electron to the 3d subshell changes the
configuration from a less stable 3d4 to a more stable half-filled 3d5 .