The special thing about the two rows directly below the periodic table is that they are lanthanoids and actinoids. They are both highly reactive with halogens and chalcogens. Actinoids react more easily, however.
Carbon appears directly below oxygen in the periodic table.
The element directly below oxygen in the periodic table is sulfur.
Sulfur appears directly below phosphorus in the periodic table.
The element directly below calcium on the periodic table is strontium. Strontium has similar chemical properties to calcium because they belong to the same group, known as alkaline earth metals.
Lead appears directly below tin on the periodic table.
Cesium. See the link below for a periodic table
See the periodic table at the link below.
All elements appear in the periodic table, there are more than 100 of them, so please look at the related link below to see an example of such table and all symbols of them.(Please note that there is no special group of 'periodic' elements)
Lanthanides and actinides are placed below the periodic table because of their unique physical and chemical properties.
The periodic table contain all chemical elements. For the table see the link below.
The "Periodic Table of the Elements". See related link below.
The two periods below the periodic table are known as the lanthanides and actinides. These series consist of elements that fall within the f-block of the periodic table.