What happens if I send a Bitcoin to an address no one owns? Say I send 1.0 BTC to a Bitcoin address that is valid but has never been used yet.


Does that 1.0 BTC effectively disappear? Or will the transaction fail?
If the transaction succeeds, could someone eventually start using that address and claim that 1.0 BTC?
If the address is valid, the transaction will succeed. If nobody knows the private key for that address, the money is lost forever. For all practical purposes, it's impossible to guess the key for an address that you made up.