( Matter ( ( has ( ( density , ) ( ( how close ) ( ( the atoms ) ( are ( packed together ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Matter)) (VP (VBZ has) (NP (NP (NN density)) (, ,) (SBAR (WHADVP (WRB how) (JJ close)) (S (NP (DT the) (NNS atoms)) (VP (VBP are) (VP (VBN packed) (ADVP (RB together)))))))) (. .)))
Matter has density, how close the atoms are packed together.
(ROOT (S (NP (NP (NNP Density)) (PP (IN of) (NP (NN matter)))) (VP (VBZ reflects) (SBAR (WHADVP (WRB how) (RB closely)) (S (VP (VBD packed) (SBAR (S (NP (NP (DT the) (NNS particles)) (PP (IN of) (NP (NN matter)))) (VP (VBP are)))))))) (. .)))