( ( Heat conduction ) ( ( can ( be ( ( ( ( understood , ) ( on ( the ( atomic level ) ) ) ) , ) ( as ( ( particles physically ) ( ( transferring ( the ( heat energy ) ) ) ( as ( they ( come ( in ( ( physical contact ) ( with ( neighboring particles ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Heat) (NNP conduction)) (VP (MD can) (VP (VB be) (VP (VBN understood) (, ,) (PP (IN on) (NP (DT the) (JJ atomic) (NN level))) (, ,) (PP (IN as) (NP (NP (NN particles) (RB physically)) (VP (VBG transferring) (NP (DT the) (NN heat) (NN energy)) (SBAR (IN as) (S (NP (PRP they)) (VP (VBP come) (PP (IN in) (NP (NP (JJ physical) (NN contact)) (PP (IN with) (NP (VBG neighboring) (NNS particles)))))))))))))) (. .)))
Heat conduction can be understood, on the atomic level, as particles physically transferring the heat energy as they come in physical contact with neighboring particles.
(ROOT (S (NP (NNP Conduction)) (VP (VBZ is) (NP (NP (DT the) (NN transfer)) (PP (IN of) (NP (NP (JJ thermal) (NN energy)) (PP (IN between) (NP (NP (NNS particles)) (PP (IN of) (NP (NN matter))))))) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (VP (VBG touching) (S (VP (VBN called))))))))) (. .)))