( ( ( 3 ( individual atoms ) ) ( -LRB- ( ( ( ( 2 ( hydrogen atoms ) ) and ) ( 1 ( oxygen atoms ) ) ) -RRB- ) ) ) ( ( are ( in ( one ( water molecule ) ) ) ) . ) )
(ROOT (S (NP (NP (CD 3) (JJ individual) (NNS atoms)) (PRN (-LRB- -LRB-) (NP (NP (CD 2) (NN hydrogen) (NNS atoms)) (CC and) (NP (CD 1) (NN oxygen) (NNS atoms))) (-RRB- -RRB-))) (VP (VBP are) (PP (IN in) (NP (CD one) (NN water) (NN molecule)))) (. .)))
3 individual atoms (2 hydrogen atoms and 1 oxygen atoms) are in one water molecule.
(ROOT (S (NP (NNP Water)) (VP (VBZ contains) (NP (CD 3) (NNS atoms))) (. .)))
Water contains 3 atoms.