Period (periodic table)

A period in the periodic table is any horizontal row of elements.

Each elements in the same period has one more proton than the one to its left. This means its atomic number is one number higher. The elements in the same period are very metallic on the left and nonmetallic on the right. The smaller atoms are on the left and the larger ones are on the right because the atoms have more protons and electrons.

The first period has 2 elements, hydrogen and helium. The second period and third period each have 8 elements. The fourth period and fifth period each have 18 elements. The sixth period and seventh period each have 32 elements. F-block elements are counted in the sixth and seventh periods. Hence, each one has 32 elements in it.

Standard periodic table

Group →

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

Period ↓

1

1 H

2 He

2

3 Li

4 Be

5 B

6 C

7 N

8 O

9 F

10 Ne

3

11 Na

12 Mg

13 Al

14 Si

15 P

16 S

17 Cl

18 Ar

4

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

5

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

6

55 Cs

56 Ba

* Lanthanides

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

7

87  Fr

88 Ra

** Actinides

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

8

119  Uue

120  Ubn

*** Superactinides

158 Upo

159 Upe

160 Uhn

161 Uhu

162 Uhb

163 Uht

164 Uhq

165 Uhp

166 Uhh

167 Uhs

168 Uho

169 Uhe

170 Usn

171 Usu

172 Usb

9

173  Ust

174  Usq

**** Eka-superactinides

212 Bub

213 But

214 Buq

215 Bup

216 Buh

217 Bus

10

227  Bbs

228  Bbo

* Lanthanide Series

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

** Actinide Series

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

*** Superactinide Series

143 Uqt

144 Uqq

145 Uqp

146 Uqh

147 Uqs

148 Uqo

149 Uqe

150 Upn

151 Upu

152 Upb

153 Upt

154 Upq

155 Upp

156 Uph

157 Ups

*** Superactinide Series

121 Ubu

122 Ubb

123 Ubt

124 Ubq

125 Ubp

126 Ubh

127 Ubs

128 Ubo

129 Ube

130 Utn

131 Utu

132 Utb

133 Utt

134 Utq

135 Utp

136 Uth

137 Uts

138 Uto

139 Ute

140 Uqn

141 Uqu

142 Uqb

Chemical Series of the Periodic Table

• Alkali metals
• Alkaline earths
• Lanthanides
• Actinides
• Superactinides
• Eka-superactinides
• Transition metals
• Poor metals
• Metalloids/Semi metals/Half metals
• Nonmetals
• Halogens
• Noble gases

State at standard temperature and pressure. The color of the number (atomic number) above the element symbol shows the state of the element at normal conditions.

• those in blue are gases
• those in green are liquids
• those in black are solid

Radioactivity

• Those with solid borders have stable isotopes (Primordial elements)
• Those with dashed borders have only radioactive naturally occurring isotopes
• Those with dotted borders do not occur naturally (Synthetic Elements)
• those without borders are too radioactive to have been discovered yet.