Protactinium

Properties
Atomic symbol |  Pa
Atomic number |  91
Classification |  Metallic
Atomic mass |  231.03588 amu
Other Information
Date of discovery |  1913
Name of discoverer |  Kasimir Fajans and O.H. Göhring
Name origin |  From the Greek Protos meaning first.
Uses |  None
Obtained from |  Occurs in minute trace amounts in uranium ores, but chiefly amongst the fission products of uranium, thorium, and plutonium. In 1961 the UK Atomic Energy Authority produced 125g of pure protactinium from uranium fuel elements, which represents the major world stock of protactinium.
Periodic Table of the Elements

1  | 2  | 3  | 4  | 5  | 6  | 7  | 8  | 9  | 10  | 11  | 12  | 13  | 14  | 15  | 16  | 17  | 18

1.008

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

4.003

6.939

9.0122

|  |  |  |  |  |  |  |  |  |  |

10.811

12.011

14.007

15.999

18.998

10.183

22.99

24.312

|  |  |  |  |  |  |  |  |  |  |

26.982

28.086

30.974

32.064

35.453

39.948

39.102

40.08

44.956

47.9

50.942

51.996

54.938

55.847

58.933

58.71

63.546

65.37

69.72

72.59

74.922

78.96

79.904

83.8

85.47

87.62

88.905

91.22

92.906

95.94

[97]

101.07

102.91

106.4

107.87

112.4

114.82

118.69

121.75

127.6

126.9

131.3

132.91

137.34

57*

138.91

178.49

180.95

183.85

186.2

190.2

192.2

195.09

196.97

200.59

204.37

207.19

208.98

210

210

222

215

226.03

89**

227.03

104

[261]

105

[262]

106

[266]

107

[264]

108

[265]

109

[268]

110

[271]

111

[272]

112

[277]

113

[284]

114

[289]

115

[288]

116

[292]

117

[293]

118

[294]

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
*Lanthanides  |

140.12

140.91

144.24

145

150.35

151.96

157.25

158.92

162.5

164.93

167.26

168.93

173.04

174.97

|  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
**Actinides  |

232.04

231

238.03

237.05

239.05

241.06

244.06

249.08

252.08

252.08

100

257.1

101

258.1

102

259.1

103

262.11

|  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |