The first to move with impact and energy (5)
I believe the answer is:
white
'the first to move' is the definition.
(white moves first in chess)
'with impact and energy' is the wordplay.
'with' becomes 'w' (abbreviation).
'impact' becomes 'hit' (hitting is a kind of impacting).
'and' means one lot of letters go next to another.
'energy' becomes 'e' (physics symbol as in E=mc2).
'w'+'hit'+'e'='WHITE'
(Other definitions for white that I've seen before include "Reflecting virtually all light" , "- Christmas, famous song" , "Colourless" , "Stainless" , "and 9: What Bing Crosby dreamed about" .)