Chapter 20: Metals and Their Compounds

(a) 19K
(b) 10 Ne
(c) 29Cu
(d) 35 Br
(e) 15P
20.8. Write down the primary oxidation states of
the following elements and check your answers in
Figure 20.4:
(a) 5B
(b) 20 Ca
(c) 17Cl
(d) 1 H
(e) 18Ar
(f) 28Ni
(g) 24 Cr
20.9. Referring to Figure 18.3, select two atoms
that are likely to have negative oxidation states because
they have very high ionization energies. Avoid the
noble gases 2 He, 10 Ne, and 18 Ar. Now look these elements
up in Figure 17.7 to see if there is a vacancy for
an electron in a low-lying orbital.
20.10. Referring to Figure 18.3, select two atoms
that are likely to have positive oxidation states because
they have low ionization energies. Now look these elements
up in Figure 17.7 to see if the top electrons are
near the top of the well.
20.11. Use Figure 20.4 to write the common oxidation
states of the following elements (e.g., He: 0; and
C: –2,0,2, and 4):
(a) N
(b) P
(c) O
(d) S
(e) Ne
(f) Ar
20.12. From Figure 17.6, state which electron Li is
likely to lose to become Li 1+ . Do the same for Be going
to Be 2+ (two electrons).
20.13. How many I – ions will be required to neutralize
the charge on an Al 3+ ion?
20.14 How many Al 3+ and O 2– ions must be combined
to achieve charge neutralization? (Hint: It will
require more than one of each type of ion.)
20.15. Write the chemical formulas for the following
combinations:
(a) K + and F –
(b) Na + and S 2–
(c) Mg 2+ and N 3–
20.16. Determine the principal oxidation states of
the following elements and then write the correct chemical
formulas for the combinations:
(a) 4Be and 35 Br
(b) 31 Ga and 8 O
20.17. Write the names of the following compounds:
(a) BeO
(b) CaCl 2
(c) LiF
(d) Na 2 S
20.18. Write the names of the following compounds:
(a) CrO
(b) CrO 3
(c) Cr 2 O 3
(d) NO 2
(e) SO 3
20.19. Complete Table 20.1.
20.20. Which of the following is an ionic compound?
(a) O 2
(b) NH 3
(c) CO 2
(d) CH 4
(e) MgF 2
is:
20.21. The correct formula for potassium sulfide
(a) KS
(b) K 2 S
(c) KS 2
(d) K 3 S
(e) KS 3
20.22. Determine the primary oxidation state for
Rb. If two Rb atoms combine with one S atom, what is
the oxidation state of S?
(a) +2
(b) +1
(c) 0
(d) –1
(e) –2
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