Oxygen

Oxygen
Identification
Symbol	O
Block	P-Block
Group	Group 16
Period	Period 2
Atomic Information
Atomic Number	8
Atomic Radius	Unknown pm
Mass	15.9999 Ar
Category	Chalcogens
Standard state(298 K)	Gas
Electronic Configuration	1s2 2s2 2p4
Electronegativity (Pauling)	Unknown
Electron affinity	Unknown
First ionisation energy	Unknown
Physical Properties
Color	Colourless
Melting Point	54.36 K
Boiling Point	90.19 K
Density of solid	Unknown
Reflectivity	Unknown
Heat Properties
Enthalpy of fusion	Unknown
Enthalpy of atomisation	Unknown
Enthalpy of vaporisation	Unknown

Oxygen is the 8^th element in the periodic element according to its atomic number. It is the second most electronegative element after Fluorine. Its electronegativity is 3.44 according to Pauling Scale. It is also a powerful oxidising agent having formed many oxides with elements readily. Under standard temperature and pressure it exists as dioxygen(O₂) which is a colorless, odourless and tasteless gas. Free elemental O₂ only began to accumulate in the atmosphere about 2.5 billion years ago during the Great Oxygenation Event, about a billion years after the first appearance of the Obligate anaerobic organisms.

Periodic Table

1 H

2 He

3 Li

4 Be

5 B

6 C

7 N

8 O

9 F

10 Ne

11 Na

12 Mg

13 Al

14 Si

15 P

16 S

17 Cl

18 Ar

19 K

20 Ca

21 Sc

22 Ti

23 V

24 Cr

25 Mn

26 Fe

27 Co

28 Ni

29 Cu

30 Zn

31 Ga

32 Ge

33 As

34 Se

35 Br

36 Kr

37 Rb

38 Sr

39 Y

40 Zr

41 Nb

42 Mo

43 Tc

44 Ru

45 Rh

46 Pd

47 Ag

48 Cd

49 In

50 Sn

51 Sb

52 Te

53 I

54 Xe

55 Cs

56 Ba

*

72 Hf

73 Ta

74 W

75 Re

76 Os

77 Ir

78 Pt

79 Au

80 Hg

81 Tl

82 Pb

83 Bi

84 Po

85 At

86 Rn

87 Fr

88 Ra

**

104 Rf

105 Db

106 Sg

107 Bh

108 Hs

109 Mt

110 Ds

111 Rg

112 Cn

113 Nh

114 Fl

115 Mc

116 Lv

117 Ts

118 Og

119 Uue

120 Ubn

***

158 Ups

159 Upo

160 Upe

161 Uhn

*

57 La

58 Ce

59 Pr

60 Nd

61 Pm

62 Sm

63 Eu

64 Gd

65 Tb

66 Dy

67 Ho

68 Er

69 Tm

70 Yb

71 Lu

**

89 Ac

90 Th

91 Pa

92 U

93 Np

94 Pu

95 Am

96 Cm

97 Bk

98 Cf

99 Es

100 Fm

101 Md

102 No

103 Lr