( ( If ( ( an electron ) ( is removed ) ) ) ( ( a cation ) ( ( is formed ) . ) ) )
(ROOT (S (SBAR (IN If) (S (NP (DT an) (NN electron)) (VP (VBZ is) (VP (VBN removed))))) (NP (DT a) (NN cation)) (VP (VBZ is) (VP (VBN formed))) (. .)))
If an electron is removed a cation is formed.
(ROOT (S (NP (NNS Cations)) (VP (VBP are) (VP (VBN formed) (PP (IN by) (NP (NP (DT the) (NN loss)) (PP (IN of) (NP (CD one) (CC or) (CD two) (NNS electrons))))) (PP (IN from) (NP (DT an) (NN element))))) (. .)))
Cations are formed by the loss of one or two electrons from an element.