( Semiconductors ( typically ( ( contain ( ( ( ( ( ( ( silicon or ) germanium ) ( -LRB- ( green -RRB- ) ) ) , ) ( elements ( with ( four ( valence electrons ) ) ) ) ) , ) ( which ( form ( ( the ( covalent bonds ) ) ( between atoms ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (NNP Semiconductors)) (ADVP (RB typically)) (VP (VBP contain) (NP (NP (NN silicon) (CC or) (NN germanium)) (PRN (-LRB- -LRB-) (ADJP (JJ green)) (-RRB- -RRB-)) (, ,) (NP (NP (NNS elements)) (PP (IN with) (NP (CD four) (JJ valence) (NNS electrons)))) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP form) (NP (NP (DT the) (JJ covalent) (NNS bonds)) (PP (IN between) (NP (NNS atoms))))))))) (. .)))
Semiconductors typically contain silicon or germanium (green) , elements with four valence electrons, which form the covalent bonds between atoms.
(ROOT (S (NP (NNP Valence)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (DT the) (NN number)) (PP (IN of) (NP (JJ covalent) (NNS bonds))))) (SBAR (S (NP (DT an) (NN atom)) (VP (MD can) (VP (VB form))))))) (. .)))
Valence is the term for the number of covalent bonds an atom can form.