Chemical elements of the fourth period
The fourth period of the periodic table of the elements contains all chemical elements that have exactly four electron shells in the atom . The innermost (first) electron shell is fully occupied and has two electrons . The second electron shell is also fully occupied and has eight electrons. The third electron shell has a minimum of eight and a maximum of 18 electrons. The outermost (fourth) electron shell, also called the valence shell , can hold between one and eight electrons. Thus there are a total of 18 chemical elements in the fourth period.
Extract from the periodic table
group | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 10 | 11 | 12 | 13 | 14th | 15th | 16 | 17th | 18th |
|
I. | II |
|
III | IV | V | VI | VII | VIII | |||||||||
Atomic number symbol |
19 K |
20 approx |
21 Sc |
22 Ti |
23 V |
24 Cr |
25 mn |
26 feet |
27 Co |
28 Ni |
29 Cu |
30 notes |
31 Ga |
32 Ge |
33 As |
34 Se |
35 Br |
36 kr |
Alkali metals | Alkaline earth metals | Transition metals | other metals | Semi-metals | Halogens | Noble gases |
Magic number
The chemical elements calcium and nickel with atomic numbers 20 and 28, respectively, have a higher stability in the basic state of the atomic nucleus than neighboring nuclides . These special ordinal numbers are called magic numbers .
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 | 8th | 2 | 6th | - | - | |
3 | 8 to 18 | 2 | 6th | 0 to 10 | - | |
4th | 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 |
---|---|---|---|---|---|
19th | K | potassium | Alkali metals | firmly | [ Ar ] 4s 1 |
20th | Approx | Calcium | Alkaline earth metals | firmly | [Ar] 4s 2 |
21st | Sc | Scandium | Transition metals | firmly | [Ar] 3d 1 4s 2 |
22nd | Ti | titanium | Transition metals | firmly | [Ar] 3d 2 4s 2 |
23 | V | Vanadium | Transition metals | firmly | [Ar] 3d 3 4s 2 |
24 | Cr | chrome | Transition metals | firmly | [Ar] 3d 5 4s 1 |
25th | Mn | manganese | Transition metals | firmly | [Ar] 3d 5 4s 2 |
26th | Fe | iron | Transition metals | firmly | [Ar] 3d 6 4s 2 |
27 | Co | Cobalt | Transition metals | firmly | [Ar] 3d 7 4s 2 |
28 | Ni | nickel | Transition metals | firmly | [Ar] 3d 8 4s 2 |
29 | Cu | copper | Transition metals | firmly | [Ar] 3d 10 4s 1 |
30th | Zn | zinc | Transition metals | firmly | [Ar] 3d 10 4s 2 |
31 | Ga | gallium | other metals | firmly | [Ar] 3d 10 4s 2 4p 1 |
32 | Ge | Germanium | Semi-metals | firmly | [Ar] 3d 10 4s 2 4p 2 |
33 | As | arsenic | Semi-metals | firmly | [Ar] 3d 10 4s 2 4p 3 |
34 | Se | selenium | Semi-metals | firmly | [Ar] 3d 10 4s 2 4p 4 |
35 | Br | bromine | Halogens | liquid | [Ar] 3d 10 4s 2 4p 5 |
36 | Kr | krypton | Noble gases | gaseous | [Ar] 3d 10 4s 2 4p 6 |