At greater distances, the protons repel each other because they are positively charged, and charges of the same kind repel.
(the protons; repel; each other; because they are positively charged, and charges of the same kind repel; L:At greater distances) (they; are positively charged; )
the protons they
repel are positively charged
each other because they are positively charged, and charges of the same kind repel L:At greater distances