1. Skills Practice Answers

2. Skills Practice 1 9,434,880 mL 17.8 cases 0.333 pallet
a) m b) 4.1x1010 c) 92,000 μm d) 91,600 nm
a) 2.229x107 b) 8.07x106 c) 5.41x1020 d) 1.12x107
a) x1010 b) 3.51x10-9
a) 235,400 b)

3. Skills Practice 2
325.2
18,000
0.0175
0.790
28,910,000 27
4.9x1012
1.86x105

4. Skills Practice 8 a) 21 b) Scandium (Sc) c) 22
Atoms of the same element (having the same number of protons) with a different number of neutrons.
a) -2 b) sulfur c) 17
1;3 +2 30
B) ions
Strontium (Sr)
Symbol
neutrons
protons
electrons
atomic #
mass #
𝐵 𝑎 +2 80 56 54
136
25 56 𝑀 𝑛 31 25
𝐴 𝑢
120 79
199
20 41 𝐶 𝑎 +2 21 20 18 41

5. Skills Practice 9 a) 74.92 amu b) Arsenic (As)
a) amu b) Chromium (Cr)
The most abundant is the one with a mass of amu.
amu

6. Skills Practice 10
Ground state: the normal energy level that an electron occupies. Excited state: when an electron has absorbed energy to occupy a higher energy level.
7.11x10-8 m
8.62x10-20 J
3.68x10-19 J
a) 8.52x1014 Hz b) 5.65x10-19 J
f=7.68x1014 Hz wavelength= 3.91x10-7 m

7. Skills Practice 11
There is no such thing as an f sublevel in the third energy level. Also, an f sublevel if it existed would have seven orbitals instead of four. 8 10 2
Orbitals = 9 Electrons =18 50 4p

8. Skills Practice 13 a. ends in: 3d
b. ends in: 4d
c. ends in: 4p
2) a. 1s22s22p63s23p64s23d4
b. 1s22s22p63s23p64s23d104p65s24d105p3
c. 1s22s22p63s23p64s2
3) Because of Hund’s Rule the 2p sublevel should look like: 1s 2s p
4) Three

9. Skills Practice 14 a. 5 b. 2 c. 6 d. 8 e. 7 a. 2-8-3 b. 2-6 c. 2-8-6
Column 14 or IVA
a. 5 dots b. 2 dots c. 4 dots d. 7 dots

10. Skills Practice 15 Abbreviated electron configurations:
[Ar] 4s23d104p2
[Xe] 6s2
[Ar] 4s23d104p5
[Xe]6s24f145d106p3
[Ar] 4s23d5
[Xe]6s24f145d9
Column 6 (or VIB)
5th row
3rd row
Each d sublevel can hold 10 electons
Each p sublevel can hold 6 electrons

11. Skills Practice 16
The second energy level feels a +13 charge and the outer energy level feels a +5 charge.
Sulfur’s outer level of electrons feels a +6 charge pulling on it from the nucleus. Silicon’s outer level feels a weaker charge of +4 and therefore it is not pulled as close to the nucleus as sulfur’s outer level.
Chlorine is lower in the periodic table which would indicate that it is larger than lithium, but it is also located further to the right which would indicate that it is smaller.
a) S, Al, Mg, Na b) C, Si, Sn, Pb c) Br, Se, Ca, K d) C, B, Be, Mg, Ca e) Cl, P, Al, Ga f) Ne, O, S, Se

12. Skills Practice 17
1. It is relatively hard to remove the first electon. 2. a) Ca, As, Se, Br b) Bi, As, P, N c) Ga, Al, Si, S d) K, Li, C, O e) Po, Te, S, O e) In, Sn, Te, I 3. Beryllium; After its two outermost electrons are removed, the next electron would need to be removed from an inner energy level, which is much more difficult. 4. Larger atoms tend to have smaller first ionization energies because the outer electrons are farther from the nucleus. Since the electrons are farther, the force of attraction from the nucleus is less.

13. Skills Practice 18 Fluorine atom: 2-7; Fluorine ion: 2-8
0; all atoms have a neutral charge. +2
-2, -1, -1, +2, +1, +2, +3, -3, -2, -1, +2, +1

14. Skills Practice 19 Ion Symbol Formulas Names Rewrite
Na2S
Mg+2
AlCl3
Rb+1
Ca3P2
F-1
BaO
Al+3
Names
S-2
Sodium sulfide
Rewrite
Aluminum chloride
BaS
Calcium phosphide
Rb3N
Barium oxide
LiCl
+1, +2, +3, +/-4, -3, -2, -1
AlN
MgBr2
Al2O3

15. Skills Practice 20 LiC2H3O2 Calcium oxide Na3PO4 Barium chloride
Mg(OH)2
Potassium phosphate
Omit
Magnesium hydroxide
(NH4)2S
K2O
Sodium acetate
AlPO4
Lithium sulfate
NaOH
Ammonium sulfate
Aluminum cyanide
Beryllium chlorate

16. Skills Practice 21 MnF4 Nickel(II) Phosphate (NH4)3PO4
Chromium(III) hydroxide
Ni(NO3)2
Barium chlorate
Na3N
Manganese(IV) nitride
Al2(SO4)3
Copper(I) carbonate
Cr(OH)3 6
Fe3(PO4)2 3
CuCl2 4
Copper(II) oxide 8
Iron(II) sulfate
Ammonium sulfide

17. Skills Practice 22 Dinitrogen pentoxide N20 Triphosphorus heptoxide
Fe(NO3)2
CCl4
Trisulfur tetrafluoride
C3H7
Carbon dioxide
H3PO4
Dinitrogen hexoxide
NO2
Copper(II) sulfate
CH2
Ammonium carbonate
C6H9O
Sulfur hexafluoride
N2H3O2
H2O4
S2O7
N3S5
C4H3O4
CO2

18. Skills Practice 28

19. Skills Practice 29

20. Skills Practice 30 7.02 x 1024 molecules 1121 grams
Quantity of particles needed to equal an element’s atomic mass in grams.
1180 grams
183.4 amu; g/mol
3.32 moles
1.22 x 1024 atoms
78.6 g/mol
4655 grams
1.81 x 1024 molecules

21. Skills Practice 31
15.4%
a- 25.8% b- 64.7%
a- 53.8% b- 34.4%
N2O5
N3O6
a- C3H4O b- C24H32O8
C18H27O36

22. Skills Practice 32
35.0 g
345 g LiNO3; 100 g Ca
117 g Na3P; 239 CaSO4
181.7 g Al(NO3)3; 142 g CaCl2
41.8 g of each product