To use all functions of this page, please activate cookies in your browser.
With an accout for my.chemeurope.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
Period (periodic table)
The elements are laid out in a series rows so that those with similar properties line up in vertical columns: this reflects the periodic recurrence of similar properties as the atomic weight increases.
Modern quantum mechanics explains these periodic trends in properties in terms of electron shells. As atomic number increases, electron shells are filled in roughly this order. The filling of each shell corresponds to a row in the table.
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p 6f 7d 7f ...
Elements adjacent to one another within a group have similar physical properties, despite their significant differences in mass. In the d-block of the periodic table, periodic trends across periods become significant, and the f-block elements show a high degree of similarity across rows (particularly the lanthanides).
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Period_(periodic_table)". A list of authors is available in Wikipedia.|