Period 1 element

From Wikipedia, the free encyclopedia

A period 1 element is one of the chemical elements in the first row (or period) of the periodic table of the elements. These elements only have the 1s orbital at ground state and thus have at most only two electrons. As such they do not obey the octet rule.

These are:

Chemical elements in the first period

Group	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
# Name	1 H																	2 He
e--conf.

Chemical series of the periodic table

Alkali metals	Alkaline earth metals	Lanthanides	Actinides	Transition metals
Poor metals	Metalloids	Nonmetals	Halogens	Noble gases

Period 1 element - Period 2 element - Period 3 element - Period 4 element - Period 5 element - Period 6 element - Period 7 element - Period 8 element

Periodic tables
Standard table | Vertical table | Table with names | Names and atomic masses (large) | Names and atomic masses (small) | Names and atomic masses (text only) | Inline F-block | Elements to 218 | Electron configurations | Metals and nonmetals | Table by blocks | Alternatives
Lists of elements
Name | Atomic symbol | Atomic number | Boiling point | Melting point | Density | Atomic mass
Groups:   1 -  2 -  3 -  4 -  5 -  6 -  7 -  8 -  9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18
Periods:  1  -  2  -  3  -  4  -  5  -  6  -  7  -  8  -  9
Series:   Alkalis  -  Alkaline earths  -  Lanthanides  -  Actinides  -  Transition metals  -  Poor metals  -  Metalloids  -  Nonmetals  -  Halogens  -  Noble gases
Blocks:  s-block  -  p-block  -  d-block  -  f-block  -  g-block