Something positive about Ben’s element (7)
I believe the answer is:
sulphur
'element' is the definition.
(sulphur is a kind of element)
'something positive about ben's' is the wordplay.
'something positive' becomes 'plus'.
'about' is a reversal indicator.
'ben' becomes 'hur' (ben hur is a religious drama film).
'plus' reversed gives 'sulp'.
'sulp'+'hur'='SULPHUR'
(Other definitions for sulphur that I've seen before include "Yellow non-metallic element" , "S (chem.)" , "Chemical element" , "Element, atomic no. 16" , "Brimstone" .)