![Simple diagram of the periodic table element groups.](http://static.sciencelearn.org.nz/images/images/000/002/140/full/Periodic-table-element-groups20161004-21536-yn0k25.jpg?1674167698)
Numbers in the squares of the periodic table are atomic numbers – to avoid clutter, only some have been included to show the basic pattern.
Numbers in the squares of the periodic table are atomic numbers – to avoid clutter, only some have been included to show the basic pattern.