Skills Practice Answers

Skills Practice 1

1. 9,434,880 mL2. 17.8 cases3. 0.333 pallet4. a) 0.1560 m b) 4.1x1010 c) 92,000 μm d) 91,600

nm5. a) 2.229x107 b) 8.07x106 c) 5.41x1020 d) 1.12x107

6. a) 2.300021x1010 b) 3.51x10-9

7. a) 235,400 b) 0.000000003400

Skills Practice 2

1. 325.22. 18,0003. 0.01754. 0.7905. 28,910,0006. 277. 4.9x1012

8. 1.86x105

Skills Practice 81. a) 21 b) Scandium (Sc) c) 222. Atoms of the same element (having the same

number of protons) with a different number of neutrons.

3. a) -2 b) sulfur c) 174. 1;35. +26. 307. B) ions8. Strontium (Sr)

Symbol neutrons protons electrons atomic # mass #

80 56 54 56 136

31 25 25 25 56

120 79 79 79 199

21 20 18 20 41

Skills Practice 9

1. a) 74.92 amu b) Arsenic (As)2. a) 51.99 amu b) Chromium (Cr)3. The most abundant is the one with a mass of

40.00 amu. 4. 41.996 amu

Skills Practice 10

1) Ground state: the normal energy level that an electron occupies. Excited state: when an electron has absorbed energy to occupy a higher energy level.

2) 7.11x10-8 m3) 8.62x10-20 J4) 3.68x10-19 J5) a) 8.52x1014 Hz b) 5.65x10-19 J6) f=7.68x1014 Hz wavelength= 3.91x10-7 m

Skills Practice 11

1) 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.

2) 83) 104) 25) Orbitals = 9 Electrons =186) 507) 4p

Skills Practice 13

1) a. ends in: 3d b. ends in: 4d c. ends in: 4p2) a. 1s22s22p63s23p64s23d4

b. 1s22s22p63s23p64s23d104p65s24d105p3 c. 1s22s22p63s23p64s2

3) Because of Hund’s Rule the 2p sublevel should look like: 1s 2s 2p4) Three

Skills Practice 14

1. a. 5 b. 2 c. 6 d. 8 e. 72. a. 2-8-3 b. 2-6 c. 2-8-63. Column 14 or IVA4. a. 5 dots b. 2 dots c. 4 dots d. 7 dots

Skills Practice 15

1. Abbreviated electron configurations: a. [Ar] 4s23d104p2

b. [Xe] 6s2

c. [Ar] 4s23d104p5

d. [Xe]6s24f145d106p3

e. [Ar] 4s23d5

f. [Xe]6s24f145d9

2. Column 6 (or VIB)3. 5th row4. 3rd row5. Each d sublevel can hold 10 electons6. Each p sublevel can hold 6 electrons

Skills Practice 16

1. The second energy level feels a +13 charge and the outer energy level feels a +5 charge.

2. 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.

3. 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.

4. 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

Skills Practice 17

1. It is relatively hard to remove the first electon. 2. a) Ca, As, Se, Br b) Bi, As, P, Nc) 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.

Skills Practice 18

1. Fluorine atom: 2-7; Fluorine ion: 2-82. 0; all atoms have a neutral charge. 3. +24. -2, -1, -1, +2, +1, +2, +3, -3, -2, -1, +2, +1