( ( As ( ( light ( from ( the Sun ) ) ) ( is ( scattered ( by ( molecules ( in ( the atmosphere ) ) ) ) ) ) ) ) ( , ( it ( ( is ( partially polarised ) ) . ) ) ) )
(ROOT (S (SBAR (IN As) (S (NP (NP (NN light)) (PP (IN from) (NP (DT the) (NNP Sun)))) (VP (VBZ is) (VP (VBN scattered) (PP (IN by) (NP (NP (NNS molecules)) (PP (IN in) (NP (DT the) (NN atmosphere))))))))) (, ,) (NP (PRP it)) (VP (VBZ is) (ADJP (RB partially) (JJ polarised))) (. .)))
As light from the Sun is scattered by molecules in the atmosphere, it is partially polarised.
(ROOT (S (NP (NNP Light)) (VP (VBZ is) (VP (VBN scattered) (PP (IN from) (NP (NP (NNS molecules)) (PP (IN in) (NP (PRP$ our) (NN atmosphere))))))) (. .)))