{| class="floatright"
! colspan=2 style="text-align:left;" | ↓ <small>Period</small>
|-
! 4
|
|-
! 5
|
|-
! 6
|
|-
! 7
|
|-
| colspan="2"|
----
Legend
{| style="text-align:center; border:0; margin:1em auto;"
|-
| style="border:; background:; padding:0 2px;" | primordial element
|-
| style="border:; background:; padding:0 2px;" | synthetic element
|}
|}
Group 8 is a group (column) of chemical elements in the periodic table. It consists of iron (Fe), ruthenium (Ru), osmium (Os) and hassium (Hs). "Group 8" is the modern standard designation for this group, adopted by the IUPAC in 1990.
Ruthenium is a very rare metal in Earth's crust. It is often found in minerals such as pentlandite and pyroxinite. It can be commercially obtained as a waste product from refining nickel.
Osmium is found in osmiridium. It can also be obtained as a waste product from refining nickel.
Hassium is extremely radioactive, and as such is not found naturally in the Earth's crust. It is produced via the bombardment of lead-208 atoms with iron-58 atoms.
Biological role
Iron is a mineral used in the human body that is essential for good health. It is a component in the proteins of hemoglobin and myoglobin, both of which are responsible for transporting oxygen around the body. Iron is a part of some hormones as well. A lack of iron in the body can cause iron deficiency anemia, and an excess of iron in the body can be toxic.
Some ruthenium-containing molecules may be used to fight cancer. Normally, however, ruthenium plays no role in the human body.