Page 3 - Water and wastewater engineering

1 18
1A 8A
1 24 Atomic number 2
H 2 Cr 13 14 15 16 17 He
1.008 52.00 Atomic mass 4.003
2A 3A 4A 5A 6A 7A
3 4 5 6 7 8 9 10
Li Be B C N O F Ne
6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18

11 12 13 14 15 16 17 18
Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar
22.99 24.31 26.98 28.09 30.97 32.07 35.45 39.95
3B 4B 5B 6B 7B 8B 1B 2B
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.93 58.69 63.55 65.41 69.72 72.64 74.92 78.96 79.90 83.80

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3

55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 (209) (210) (222)

87 88 89 104 105 106 107 108 109 110 111 112 (113) 114 (115) 116 (117) 118
Fr Ra Ac Rf Db Sg Bh Hs Mt
(223) (226) (227) (261) (262) (266) (262) (277) (268)

58 59 60 61 62 63 64 65 66 67 68 69 70 71
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
140.1 140.9 144.2 (145) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0

90 91 92 93 94 95 96 97 98 99 100 101 102 103
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
232.0 (231) 238.0 (237) (242) (243) (247) (247) (251) (252) (257) (258) (259) (262)

The 1–18 group designation has been recommended by the International Union of Pure and Applied Chemistry (IUPAC) but is not yet in wide use. No names have been assigned
for elements 110–112, 114, 116, and 118. Elements 113, 115, and 117 have not yet been synthesized.
Source: Chang, R. Chemistry, 7th ed. Copyright © 2002 The McGraw-Hill Companies, Inc. New York. Reproduced wih permission.