...also the carbon bond is very special and allows for all manner of molecules. Silicon is in the same column of the periodic chart so there is speculation there might be silicon based beings, but I don’t expect there will be uranium based beings on anyone’s radar.
I suspect that a lot of the ‘aliens’ in ancient stories didn’t require what we consider ‘physical needs’. When we assumed such, we were just giving them *stuff* which - from our perspective - would appease them and allow us to remain in their good graces :-)
https://www.gutenberg.org/files/34853/34853-h/34853-h.htm