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 →123456789101112131415161718Period ↓11H2He23Li4Be5B6C7N8O9F10Ne311Na12Mg13Al14Si15P16S17Cl18Ar419K20Ca21Sc22Ti23V24Cr25Mn26Fe27Co28Ni29Cu30Zn31Ga32Ge33As34Se35Br36Kr537Rb38Sr39Y40Zr41Nb42Mo43Tc44Ru45Rh46Pd47Ag48Cd49In50Sn51Sb52Te53I54Xe655Cs56Ba*
Lanthanides72Hf73Ta74W75Re76Os77Ir78Pt79Au</td>80Hg81Tl82Pb83Bi84Po85At86Rn787 Fr88Ra**
Actinides104Rf105Db106Sg107Bh108Hs109Mt110Ds111Rg112Cn113Nh114Fl115Mc116Lv117Ts118Og8119 Uue120 Ubn***
Superactinides158Upo159Upe160Uhn161Uhu162Uhb163Uht164Uhq165Uhp166Uhh167Uhs168Uho169Uhe170Usn171Usu172Usb9173 Ust174 Usq****
Eka-superactinides212Bub213But214Buq215Bup216Buh217Bus10227 Bbs228 Bbo* Lanthanide Series57La58Ce59Pr60Nd61Pm62Sm63Eu64Gd65Tb66Dy67Ho68Er69Tm70Yb71Lu** Actinide Series89Ac90Th91Pa92U93Np94Pu95Am96Cm97Bk98Cf99Es100Fm101Md102No103Lr*** Superactinide Series143Uqt144Uqq145Uqp146Uqh147Uqs148Uqo149Uqe150Upn151Upu152Upb153Upt154Upq155Upp156Uph157Ups

*** Superactinide Series121Ubu122Ubb123Ubt124Ubq125Ubp126Ubh127Ubs128Ubo129Ube130Utn131Utu132Utb133Utt134Utq135Utp136Uth137Uts138Uto139Ute140Uqn141Uqu142Uqb

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.
Category:Periodic table
Category:Physics