Professional heavyweight makes a bit of a positive charge (6)
I believe the answer is:
proton
'a bit of a positive charge' is the definition.
I can't judge whether this defines the answer.
'professional heavyweight' is the wordplay.
'professional' becomes 'pro' (synonyms).
'heavyweight' becomes 'ton' (a ton weighs a lot).
'pro'+'ton'='PROTON'
'makes' is the link.
Can you help me to learn more?
(Other definitions for proton that I've seen before include "Particle in atoms" , "Positive nucleon" , "Nuclear particle with positive charge" , "Positively-charged particle" , "Stable subatomic particle" .)