Periodic table block
f-block elements
The f-block holds the lanthanides and actinides, the two rows usually printed beneath the main table, where 4f and 5f subshells fill. An f subshell holds up to fourteen electrons, so each row is fourteen elements long by the block's usual definition. The lanthanides are chemically similar rare earth metals, while every actinide is radioactive.
At a glance
- Elements
- 28
- Atomic numbers
- 57 to 102
- Block
- f-block
- Periods
- 6, 7
- Phase at STP
- solid (25)
Shared properties
- Electrons fill 4f and 5f subshells, which hold up to fourteen electrons
- Printed as two separate rows below the main body of the table
- Lanthanides share very similar chemistry dominated by +3 ions
- All actinides are radioactive, and most beyond uranium are synthetic