Chemical elements of the second period

from Wikipedia, the free encyclopedia

The second period of the periodic table of the elements contains all chemical elements that have exactly two electron shells in the atom . The innermost (first) electron shell is fully occupied and has two electrons . The outermost (second) electron shell, also known as the valence shell , can hold between one and eight electrons, which is why there are eight chemical elements in the second period. In order to be able to remember the elements of the second period (without neon), the following mnemonic is known: " Li ebe Be rta, B itte k ( C ) OMM N maybe O teeth F luor."

Extract from the periodic table

group 1 2 13 14th 15th 16 17th 18th

I. II III IV V VI VII VIII
Atomic number
symbol 		3
li 		4
Be 		5
B 		6
C 		7
N. 		8
O 		9
F. 		10
Ne


Alkali metals Alkaline earth metals Semi-metals other non-metals Halogens Noble gases

Magic number

The chemical element oxygen with atomic number eight has a higher stability in the basic state of the atomic nucleus than neighboring nuclides . This particular ordinal number is known as the magic number .

Number of electrons in the electron shells

Electron shell Number of electrons comment
All in all s orbital p orbital d orbital f orbital
1 2 2 - - - innermost electron shell
2 1 to 8 1 to 2 0 to 6 - - outermost electron shell , valence shell

list

Atomic number symbol Surname Element category Physical state Electron configuration
3 Li lithium Alkali metals firmly [ He ] 2s 1
4th Be beryllium Alkaline earth metals firmly [He] 2s 2
5 B. boron Semi-metals firmly [He] 2s 2 2p 1
6th C. carbon other non-metals firmly [He] 2s 2 2p 2
7th N nitrogen other non-metals gaseous [He] 2s 2 2p 3
8th O oxygen other non-metals gaseous [He] 2s 2 2p 4
9 F. fluorine Halogens gaseous [He] 2s 2 2p 5
10 No neon Noble gases gaseous [He] 2s 2 2p 6