What type of ribs pairs 11-12 that connect to the vertebrae in the back but are free of any attachment in the front is known as what?

The rib pairs that attach to the back vertebrae but are not connected to the sternum are known as floating ribs. In human anatomy, the 11th and 12th rib pairs are termed floating ribs. There are 12 pairs of ribs. The floating ribs are the lowest two rib pairs that are also called false ribs.