( So ( ( ( an atom ) ( of ( ( ( potassium-40 ( -LRB- ( K40 -RRB- ) ) ) , ) ( atomic ( number 19 ) ) ) ) ) ( ( can ( absorb ( an ( electron ( to ( become ( ( an atom ) ( of ( ( ( argon-40 ( -LRB- ( Ar40 -RRB- ) ) ) , ) ( atomic ( number 18 ) ) ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (IN So) (NP (NP (DT an) (NN atom)) (PP (IN of) (NP (NP (NP (JJ potassium-40)) (PRN (-LRB- -LRB-) (NP (NNP K40)) (-RRB- -RRB-))) (, ,) (NP (JJ atomic) (NN number) (CD 19))))) (VP (MD can) (VP (VB absorb) (NP (DT an) (NN electron) (S (VP (TO to) (VP (VB become) (NP (NP (DT an) (NN atom)) (PP (IN of) (NP (NP (JJ argon-40) (-LRB- -LRB-) (NNS Ar40) (-RRB- -RRB-)) (, ,) (NP (JJ atomic) (NN number) (CD 18))))))))))) (. .)))
So an atom of potassium-40 (K40), atomic number 19 can absorb an electron to become an atom of argon-40 (Ar40), atomic number 18.
(ROOT (S (NP (NP (DT The) (JJ low) (JJ atomic) (NN number)) (PP (IN of) (NP (NN beryllium)))) (VP (VBZ allows) (S (NP (PRP it)) (VP (TO to) (VP (VB absorb) (NP (NNPS x-rays)))))) (. .)))