( ( When ( atoms ( ( share ( ( electrons ( as they ) ) bond ) ) together ) ) ) ( , ( this ( ( is ( called ( a ( covalent bond ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS atoms)) (VP (VBP share) (NP (ADJP (JJ electrons) (PP (IN as) (NP (PRP they)))) (NN bond)) (PRT (RP together))))) (, ,) (NP (DT this)) (VP (VBZ is) (VP (VBN called) (NP (DT a) (JJ covalent) (NN bond)))) (. .)))
When atoms share electrons as they bond together, this is called a covalent bond .
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS electrons)) (VP (VBP are) (VP (VBN shared) (ADVP (RB equally)))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (NP (NN nonpolar) (NNS bonds)))) (. .)))