Whiff of sodium beginning to develop? (7)
I believe the answer is:
nascent
'beginning to develop?' is the definition.
(nascent means developing or new)
'whiff of sodium' is the wordplay.
I cannot quite understand how this works, but
'whiff' could be 'scent' (I've seen this in another clue) and 'scent' is present in the answer.
'sodium' could be 'na' (chemical symbol) and 'na' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for nascent that I've seen before include "being coined" , "Dawning" , "Starting existence" , "Beginning to show signs of potential" , "Coming alive" .)