Environmental Engineering FOURTH EDITION

Elements of the Periodic Table 453

Symbol Atomic number Atomic weight

Platinum
Plutonium
Polonium
Potassium
Praseodymium
Promethium
Protactinium
Radium
Radon
Rhenium
Rhodium
Rubidium
Ruthenium
Rutherfordium
Samarium
scandium
Seaborgium
Selenium
Silicon
Silver
sodium
Strontium
Sulfur
Tantalum
Technetium
Tellurium
Terbium
Thallium
Thorium
Thulium
Tin
Titanium
Tungsten
Uranium
Vanadium
Xenon
Ytterbium
Yttrium
Zinc
Zirconium

Pt

Pu

Po

K

Pr

Pm

Pa

Ra

Rn

Re

Rh

Rb

Ru

Rf

Sm

sc

Se

Si

Na

Sr

S

Ta

Tc

Te

Tb

T1

Th

Tm

Sn

Ti

w

U

V

Xe

Yb

Y

Zn

Zr

sg

Ag

78

94

84

19

59

61

91

88

86

75

45

37

44

104

62

21

106

34

14

47

11

38

16

73

43

52

65

81

90

69

50

22

74

92

23

54

70

39

30

40

195.08

238'

209'

39.1

140.91

23 1.03'

22ga

222a

186.2

102.91

85.47

102.91

150.55

44.96

78.96

28.09

107.87

23.0

87.62

32.06

180.95

99'

127.6

158.92

204.38

232.04

168.93

118.69

47.9

183.85

238.03'

50.94

131.3

173.04

88.91

65.37

91.22

b

b

b

=All isotopes of these elements are radioactive. Where the mass is presented as an integer, it is the

bAll isotopes of these elements are so short-lived that no mass number is given.

closest approximation.