# 9.E: Homework Chapter 9 Answers

$$\newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }$$

$$\newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}}$$

$$\newcommand{\id}{\mathrm{id}}$$ $$\newcommand{\Span}{\mathrm{span}}$$

( \newcommand{\kernel}{\mathrm{null}\,}\) $$\newcommand{\range}{\mathrm{range}\,}$$

$$\newcommand{\RealPart}{\mathrm{Re}}$$ $$\newcommand{\ImaginaryPart}{\mathrm{Im}}$$

$$\newcommand{\Argument}{\mathrm{Arg}}$$ $$\newcommand{\norm}[1]{\| #1 \|}$$

$$\newcommand{\inner}[2]{\langle #1, #2 \rangle}$$

$$\newcommand{\Span}{\mathrm{span}}$$

$$\newcommand{\id}{\mathrm{id}}$$

$$\newcommand{\Span}{\mathrm{span}}$$

$$\newcommand{\kernel}{\mathrm{null}\,}$$

$$\newcommand{\range}{\mathrm{range}\,}$$

$$\newcommand{\RealPart}{\mathrm{Re}}$$

$$\newcommand{\ImaginaryPart}{\mathrm{Im}}$$

$$\newcommand{\Argument}{\mathrm{Arg}}$$

$$\newcommand{\norm}[1]{\| #1 \|}$$

$$\newcommand{\inner}[2]{\langle #1, #2 \rangle}$$

$$\newcommand{\Span}{\mathrm{span}}$$ $$\newcommand{\AA}{\unicode[.8,0]{x212B}}$$

$$\newcommand{\vectorA}[1]{\vec{#1}} % arrow$$

$$\newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow$$

$$\newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }$$

$$\newcommand{\vectorC}[1]{\textbf{#1}}$$

$$\newcommand{\vectorD}[1]{\overrightarrow{#1}}$$

$$\newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}}$$

$$\newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}}$$

$$\newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }$$

$$\newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}}$$

1. a) gamma rays

3. Gamma rays < X-rays < Ultraviolet < Visible Light < Infrared < Microwaves < Radio Waves

The Quantum Mechanical Model

5.

Electron Configurations

7. a) Li: 1s22s1

b) N: 1s22s22p3

c) Cl: 1s22s22p63s23p5

d) Ga: 1s22s22p63s23p64s23d104p1

9. a) Xe: 1s22s22p63s23p64s23d104p65s24d105p6

b) Ag: 1s22s22p63s23p64s23d104p65s24d9

c) Cs: 1s22s22p63s23p64s23d104p65s24d105p66s1

d) Hg: 1s22s22p63s23p64s23d104p65s24d105p66s24f145d10

11.

a) P:

1s         2s                       2p                      3s                       3p

↑↓         ↑↓              ↑↓         ↑↓         ↑↓         ↑↓         ↑           ↑              ↑

3 unpaired electrons

b) K:

1s         2s                       2p                      3s                       3p                      4s

↑↓         ↑↓             ↑↓         ↑↓         ↑↓         ↑↓         ↑↓         ↑↓              ↑↓         ↑_

1 unpaired electron

c) He:

1s

↑↓

No unpaired electrons

d) Al:

1s         2s                       2p                      3s                       3p

↑↓         ↑↓           ↑↓         ↑↓         ↑↓            ↑↓         ↑

1 unpaired electron

13. a) Nb: [Kr] 5s24d3

b) Se: [Ar] 4s23d104p4

c) Ca: [Ar] 4s1

d) Zn: [Ar] 4s23d10

15. Write the noble gas electron configuration for the following elements.

a) In: [Kr] 5s24d105p1

b) Ba: [Xe] 6s2

c) V: [Ar] 4s23d3

d) Y: [Kr] 5s24d1

Valence Electrons

17. a) Cd:

5s

↑↓

No unpaired electrons

b) Na:

3s

↑_

1 unpaired electron

c) I:

5s                       5p

↑↓            ↑↓         ↑↓         ↑_

1 unpaired electron

d) Sn:

5s                       5p

↑↓            ↑           ↑           __

2 unpaired electrons

Electron Configurations and the Period Table

19. a) 1A: _s1

b) 5A: _s2_p3

c) 6A: _s2_p4

21. a) 8A: _s2_p6

b) 2A: _s2

23. a) Ra: [Rn] 7s2

b) Pd: [Kr] 5s24d8

c) Br: [Ar] 4s23d104p5

d) Po: [Xe] 6s24f145d106p4

25. a) At: [Xe] 6s24f145d106p5

b) Pb: [Xe] 6s24f145d106p2

c) Ba: [Xe] 6s2

d) Ce: [Xe] 6s24f1

27. a) Re: [Xe] 6s24f145d5

b) Al: [Ne] 3s23p1

c) Lr: [Rn] 7s25f14

d) Os: [Xe] 6s24f145d6

29. a) Mg: 2                  b) K: 2                            c) Na: 1

d) Li: Lithium does not have a 3s orbital shell, therefore there are zero 3s electrons

31. a) Te                        b) Sr                               c) Nb                              d) In

33. a) As                        b) Ge                              c) Cu                               d) K

35. a) No                       b) C                                 c) Kr                               d) W

Periodic Trends

37. a) Rb                       b) Te                               c) Ge                               d) Pb

39. a) Y                          b) K                                 c) Tc                               d)  Cs

41. O < Kr < Be < Sr < K

Cumulative Challenge Problems

43. a) n=1, 2                 b) n=2, 8                        c) n=3, 18                      d) n=4, 32

45. a) Mn2+: [Ar] 3d5

b) Al3+: [He] 2s22p6 or         [Ne]

c) I-: [Kr] 5s24d105p6             or         [Xe]

d) Li+: [He]

47. P3- ,S2- ,Cl- , K+ , Ca2+

9.E: Homework Chapter 9 Answers is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.