FIELD NOTES / 02
Reading the periodic table
Find your way through groups and periods.
The table is arranged by increasing atomic number. Horizontal rows are periods. Vertical columns are groups, numbered 1 to 18.
Elements in a group often have related chemical behaviour, especially among the main-group elements. Electron arrangements help explain these similarities.
The lanthanide and actinide series belong to periods 6 and 7. They are placed below the main table to make the layout compact. This site does not assign a numbered group to every member of these displayed series.