Blockchain Explorer Course https://k12.instructure.com/eportfolios/1098588/entries/3707785 Solana: Generally a number of seconds into a minute. Even so, in rare cases, Solana blockchain transactions can remain unconfirmed for hours or perhaps days These transactions remain in the mempool (memory pool) until a miner or validator selects them and contains them in a block. https://myspace.com/vincentfournier4