( ( From ( such experiments ) ) ( , ( it ( ( is ( known ( that ( ( ( protons and ) neutrons ) ( are ( made ( of ( ( smaller particles ) ( ( called quarks ) ( while ( ( the electron ) ( is ( ( a ( ( truly fundamental ) particle ) ) ( that ( ( is not ) ( made ( of ( anything smaller ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN From) (NP (JJ such) (NNS experiments))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN known) (SBAR (IN that) (S (NP (NNS protons) (CC and) (NNS neutrons)) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NP (JJR smaller) (NNS particles)) (VP (VBN called) (NP (NNS quarks)) (SBAR (IN while) (S (NP (DT the) (NN electron)) (VP (VBZ is) (NP (NP (DT a) (ADJP (RB truly) (JJ fundamental)) (NN particle)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (RB not) (VP (VBN made) (PP (IN of) (NP (NP (NN anything)) (ADJP (JJR smaller))))))))))))))))))))) (. .)))
From such experiments, it is known that protons and neutrons are made of smaller particles called quarks while the electron is a truly fundamental particle that is not made of anything smaller.
(ROOT (S (NP (NNS Protons) (CC and) (NNS neutrons)) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NP (NNS quarks)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (NP (NP (JJ fundamental) (NNS particles)) (PP (IN of) (NP (NN matter))))))))))) (. .)))