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** ↓|colspan="20"||||||||||||||||||||||||||||||||||||
|**1**|style="background-color:#a0ffa0;color:blue;border:1px solid black;"|1 H|colspan="16"||style="background-color:#c0ffff;color:blue;border:1px solid black;"|2 He|||||||||||||||||||||||||||||||
|**2**|style="background-color:#f66;border:1px solid black;"|3 Li|style="background-color:#ffdead;border:1px solid black;"|4 Be|colspan="10"||style="background-color:#cc9;border:1px solid black;"|5 B|style="background-color:#a0ffa0;border:1px solid black;"|6 C|style="background-color:#a0ffa0;color:blue;border:1px solid black;"|7 N|style="background-color:#a0ffa0;color:blue;border:1px solid black;"|8 O|style="background-color:#ff9;color:blue;border:1px solid black;"|9 F|style="background-color:#c0ffff;color:blue;border:1px solid black;"|10 Ne|||||||||||||||||||
|**3**|style="background-color:#f66;border:1px solid black;"|11 Na|style="background-color:#ffdead;border:1px solid black;"|12 Mg|colspan="10"||style="background-color:#ccc;border:1px solid black;"|13 Al|style="background-color:#cc9;border:1px solid black;"|14 Si|style="background-color:#a0ffa0;border:1px solid black;"|15 P|style="background-color:#a0ffa0;border:1px solid black;"|16 S|style="background-color:#ff9;color:blue;border:1px solid black;"|17 Cl|style="background-color:#c0ffff;color:blue;border:1px solid black;"|18 Ar|||||||||||||||||||
|**4**|style="background-color:#f66;border:1px solid black;"|19 K|style="background-color:#ffdead;border:1px solid black;"|20 Ca|style="background-color:#ffc0c0;border:1px solid black;"|21 Sc|style="background-color:#ffc0c0;border:1px solid black;"|22 Ti|style="background-color:#ffc0c0;border:1px solid black;"|23 V|style="background-color:#ffc0c0;border:1px solid black;"|24 Cr|style="background-color:#ffc0c0;border:1px solid black;"|25 Mn|style="background-color:#ffc0c0;border:1px solid black;"|26 Fe|style="background-color:#ffc0c0;border:1px solid black;"|27 Co|style="background-color:#ffc0c0;border:1px solid black;"|28 Ni|style="background-color:#ffc0c0;border:1px solid black;"|29 Cu|style="background-color:#ffc0c0;border:1px solid black;"|30 Zn|style="background-color:#ccc;border:1px solid black;"|31 Ga|style="background-color:#cc9;border:1px solid black;"|32 Ge|style="background-color:#cc9;border:1px solid black;"|33 As|style="background-color:#a0ffa0;border:1px solid black;"|34 Se|style="background-color:#ff9;color:green;border:1px solid black;"|35 Br|style="background-color:#c0ffff;color:blue;border:1px solid black;"|36 Kr|
|**5**|style="background-color:#f66;border:1px solid black;"|37 Rb|style="background-color:#ffdead;border:1px solid black;"|38 Sr|style="background-color:#ffc0c0;border:1px solid black;"|39 Y|style="background-color:#ffc0c0;border:1px solid black;"|40 Zr|style="background-color:#ffc0c0;border:1px solid black;"|41 Nb|style="background-color:#ffc0c0;border:1px solid black;"|42 Mo|style="background-color:#ffc0c0;border:1px dashed black;"|43 Tc|style="background-color:#ffc0c0;border:1px solid black;"|44 Ru|style="background-color:#ffc0c0;border:1px solid black;"|45 Rh|style="background-color:#ffc0c0;border:1px solid black;"|46 Pd|style="background-color:#ffc0c0;border:1px solid black;"|47 Ag|style="background-color:#ffc0c0;border:1px solid black;"|48 Cd|style="background-color:#ccc;border:1px solid black;"|49 In|style="background-color:#ccc;border:1px solid black;"|50 Sn|style="background-color:#cc9;border:1px solid black;"|51 Sb|style="background-color:#cc9;border:1px solid black;"|52 Te|style="background-color:#ff9;border:1px solid black;"|53 I|style="background-color:#c0ffff;color:blue;border:1px solid black;"|54 Xe|
|**6**|style="background-color:#f66;border:1px solid black;"|55 Cs|style="background-color:#ffdead;border:1px solid black;"|56 Ba|style="vertical-align: top; background-color:#ffbfff;1px;"|* Lanthanides|style="background-color:#ffc0c0;border:1px solid black;"|72 Hf|style="background-color:#ffc0c0;border:1px solid black;"|73 Ta|style="background-color:#ffc0c0;border:1px solid black;"|74 W|style="background-color:#ffc0c0;border:1px solid black;"|75 Re|style="background-color:#ffc0c0;border:1px solid black;"|76 Os|style="background-color:#ffc0c0;border:1px solid black;"|77 Ir|style="background-color:#ffc0c0;border:1px solid black;"|78 Pt|style="background-color:#ffc0c0;border:1px solid black;"|79 Au</td>|style="background-color:#ffc0c0;color:green;border:1px solid black;"|80 Hg|style="background-color:#ccc;border:1px solid black;"|81 Tl|style="background-color:#ccc;border:1px solid black;"|82 Pb|style="background-color:#ccc;border:1px dashed black;"|83 Bi|style="background-color:#cc9;border:1px dashed black;"|84 Po|style="background-color:#ff9;border:1px dashed black;"|85 At|style="background-color:#c0ffff;color:blue;border:1px dashed black;"|86 Rn|
|**7**|style="background-color:#f66;border:1px dashed black;"|87  Fr|style="background-color:#ffdead;border:1px dashed black;"|88 Ra|style="vertical-align: top; background-color:#f9c;1px;"|** Actinides|style="background-color:#ffc0c0;border:1px dotted black;"|104 Rf|style="background-color:#ffc0c0;border:1px dotted black;"|105 Db|style="background-color:#ffc0c0;border:1px dotted black;"|106 Sg|style="background-color:#ffc0c0;border:1px dotted black;"|107 Bh|style="background-color:#ffc0c0;border:1px dotted black;"|108 Hs|style="background-color:#ffc0c0;border:1px dotted black;"|109 Mt|style="background-color:#ffc0c0;border:1px dotted black;"|110 Ds|style="background-color:#ffc0c0;border:1px dotted black;"|111 Rg|style="background-color:#ffc0c0;color:green;border:1px dotted black;"|112 Cn|style="background-color:#ccc;border:1px dotted black;"|113 Nh|style="background-color:#ccc;;color:blue;border:1px dotted black;"|114 Fl|style="background-color:#ccc;border:1px dotted black;"|115 Mc|style="background-color:#ccc;border:1px dotted black;"|116 Lv|style="background-color:#ccc;border:1px dotted black;"|117 Ts|style="background-color:#c0ffff;border:1px dotted black;"|118 Og|
|**8**|style="background-color:#f66;border:none;"|119  Uue|style="background-color:#ffdead;border:none;"|120  Ubn|style="vertical-align: top; background-color:#cc70cc;1px;"|*** Superactinides|style="background-color:#ffc0c0;border:none;"|158 Upo|style="background-color:#ffc0c0;border:none;"|159 Upe|style="background-color:#ffc0c0;border:none;"|160 Uhn|style="background-color:#ffc0c0;border:none;"|161 Uhu|style="background-color:#ffc0c0;border:none;"|162 Uhb|style="background-color:#ffc0c0;border:none;"|163 Uht|style="background-color:#ffc0c0;border:none;"|164 Uhq|style="background-color:#ffc0c0;border:none;"|165 Uhp|style="background-color:#ffc0c0;border:none;"|166 Uhh|style="background-color:#ccc;border:none;"|167 Uhs|style="background-color:#ccc;border:none;"|168 Uho|style="background-color:#ccc;border:none;"|169 Uhe|style="background-color:#ccc;border:none;"|170 Usn|style="background-color:#ccc;border:none;"|171 Usu|style="background-color:#c0ffff;border:none;"|172 Usb|
|**9**|style="background-color:#f66;border:none;"|173  Ust|style="background-color:#ffdead;border:none;"|174  Usq|style="vertical-align: top; background-color:#d1ddff;1px;"|**** Eka-superactinides|style="background-color:#ffc0c0;border:none;"|212 Bub|style="background-color:#ffc0c0;border:none;"|213 But|style="background-color:#ffc0c0;border:none;"|214 Buq|style="background-color:#ffc0c0;border:none;"|215 Bup|style="background-color:#ffc0c0;border:none;"|216 Buh|style="background-color:#ffc0c0;border:none;"|217 Bus|||||||||||||||||||
|**10**|style="background-color:#f66;border:none;"|227  Bbs|style="background-color:#ffdead;border:none;"|228  Bbo|||||||||||||||||||||||||||||||||
|colspan="21"|||||||||||||||||||||||||||||||||||||
|colspan="4" style="text-align:right"|* **Lanthanide Series**|style="background-color:#ffbfff;border:1px solid black;"|57 La|style="background-color:#ffbfff;border:1px solid black;"|58 Ce|style="background-color:#ffbfff;border:1px solid black;"|59 Pr|style="background-color:#ffbfff;border:1px solid black;"|60 Nd|style="background-color:#ffbfff;border:1px dashed black;"|61 Pm|style="background-color:#ffbfff;border:1px solid black;"|62 Sm|style="background-color:#ffbfff;border:1px solid black;"|63 Eu|style="background-color:#ffbfff;border:1px solid black;"|64 Gd|style="background-color:#ffbfff;border:1px solid black;"|65 Tb|style="background-color:#ffbfff;border:1px solid black;"|66 Dy|style="background-color:#ffbfff;border:1px solid black;"|67 Ho|style="background-color:#ffbfff;border:1px solid black;"|68 Er|style="background-color:#ffbfff;border:1px solid black;"|69 Tm|style="background-color:#ffbfff;border:1px solid black;"|70 Yb|style="background-color:#ffbfff;color:blue;border:1px solid black;"|71 Lu||||||
|colspan="4" style="text-align:right"|** **Actinide Series**|style="background-color:#f9c;border:1px dashed black;"|89 Ac|style="background-color:#f9c;border:1px dashed black;"|90 Th|style="background-color:#f9c;border:1px dashed black;"|91 Pa|style="background-color:#f9c;border:1px dashed black;"|92 U|style="background-color:#f9c;border:1px dashed black;"|93 Np|style="background-color:#f9c;border:1px dashed black;"|94 Pu|style="background-color:#f9c;border:1px dotted black;"|95 Am|style="background-color:#f9c;border:1px dotted black;"|96 Cm|style="background-color:#f9c;border:1px dotted black;"|97 Bk|style="background-color:#f9c;border:1px dotted black;"|98 Cf|style="background-color:#f9c;border:1px dotted black;"|99 Es|style="background-color:#f9c;border:1px dotted black;"|100 Fm|style="background-color:#f9c;border:1px dotted black;"|101 Md|style="background-color:#f9c;border:1px dotted black;"|102 No|style="background-color:#f9c;border:1px dotted black;"|103 Lr||||||
|colspan="4" style="text-align:right"|*** **Superactinide Series**|style="background-color:#cc70cc;border:none;"|143 Uqt|style="background-color:#cc70cc;border:none;"|144 Uqq|style="background-color:#cc70cc;border:none;"|145 Uqp|style="background-color:#cc70cc;border:none;"|146 Uqh|style="background-color:#cc70cc;border:none;"|147 Uqs|style="background-color:#cc70cc;border:none;"|148 Uqo|style="background-color:#cc70cc;border:none;"|149 Uqe|style="background-color:#cc70cc;border:none;"|150 Upn|style="background-color:#cc70cc;border:none;"|151 Upu|style="background-color:#cc70cc;border:none;"|152 Upb|style="background-color:#cc70cc;border:none;"|153 Upt|style="background-color:#cc70cc;border:none;"|154 Upq|style="background-color:#cc70cc;border:none;"|155 Upp|style="background-color:#cc70cc;border:none;"|156 Uph|style="background-color:#cc70cc;border:none;"|157 Ups||||||

- Chemical Series of the Periodic Table

- <div style="background-color:#f66">Alkali metals</div>
- <div style="background-color:#ffdead">Alkaline earths</div>
- <div style="background-color:#ffbfff">Lanthanides</div>
- <div style="background-color:#f9c">Actinides</div>
- <div style="background-color:#cc70cc">Superactinides</div>
- <div style="background-color:#d1ddff">Eka-superactinides</div>
- <div style="background-color:#ffc0c0">Transition metals</div>
- <div style="background-color:#ccc">Poor metals</div>
- <div style="background-color:#cc9">Metalloids/Semi metals/Half metals</div>
- <div style="background-color:#a0ffa0">Nonmetals</div>
- <div style="background-color:#ff9">Halogens</div>
- <div style="background-color:#c0ffff">Noble gases</div>

- 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 <span style="color:blue;">blue</span> are gases
- those in <span style="color:green;">green</span> are liquids
- those in <span style="color:black;">black</span> are solid

- Radioactivity

- <div style="border:solid 1px black;padding:1px;">Those with solid borders have stable isotopes (Primordial elements)</div>
- <div style="border:dashed 1px black;padding:1px;">Those with dashed borders have only radioactive naturally occurring isotopes</div>
- <div style="border:dotted 1px black;padding:1px;">Those with dotted borders do not occur naturally (Synthetic Elements)</div>
- <div style="border:none;padding:1px;">those without borders are too radioactive to have been discovered yet.</div>