21a Radioactive metal from which most of a fissile isotope has been removed 8,7 I have ?E?L?T?D ?R?N?U? I think the last word is uranium.
2d Atom with valency of five. 5 letters ending in D. I don't understand the clue but is the answer bonded?
As you can see I am no scientist! Any help would be appreciated. many thanks