Potassium

Properties
Atomic symbol |  K
Atomic number |  19
Classification |  Alkali metal
Atomic mass |  39.10 amu
Other Information
Date of discovery |  1807
Name of discoverer |  Davy, Sir Humphrey
Name origin |  From the Latin Kalium
Uses |  important biological role, and used in numerous industrial processes
Obtained from |  sylvite, sylvinite, carnallite

Potassium is an element[1] in the alkali metals class of the periodic table. It is so chemically active that it is never found free (in elemental form) in nature. In its elemental form, it reacts with water, forming potassium hydroxide and hydrogen gas, so violently that the hydrogen usually catches fire. It reacts with the halogens to make halides like potassium chloride.

Its existence as "potash" or "vegetable alkali" (potassium carbonate), "caustic potash" (potassium hydroxide), etc., had long been known, but it was not isolated as an element until 1807, by Sir Humphrey Davy. It was isolated by electrolysis of potassium hydroxide.

The radioactive decay of potassium provides a method of radiometric dating called potassium-argon dating that is used to calculate the ages of volcanic rocks.

## See also[edit]

* List of gardening topics
* Permaculture \- Permanent agriculture
* Soil fertility \- nitrogen, phosphorus, potassium

## References[edit]

1. ↑ Wile, Dr. Jay L. Exploring Creation With Physical Science. Apologia Educational Ministries, Inc. 1999, 2000

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

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