Why Senku and Taiju revived from petrification when everybody else needed Senku's formula to revive? People who survived petrification were revived using Senku's formula, with the exception of Senku and Taiju. How were they able to revive without any formula?
Taiju at least break the stone with the water drops from the cave he was in... and this water is the base of the Senku's formula.

It is explained by the Senku itself in the 2º episode of the anime (From memory i think is the 2º episode, but maybe id the third).