guess the metal (and solvent for bonus arylpoints) 👇
@aryl sodium in ethylenediamine?
@mxchara i think that exact reaction doesn't work with sodium in En... you'd have to go to lithium for it

@aryl hm, are you sure?

https://pubs.acs.org/doi/10.1021/j100650a008

this seems to imply that Na dissolves in ethylenediamine