Simplify the following text for a Grade 11 native English-speaking person.
Original: Sir James Chadwick CH FRS ( 20 October 1891 -- 24 July 1974 ) was an English Nobel laureate in physics awarded for his discovery of the neutron .
Simplified: Sir James Chadwick , ( born 20 October 1891 ; died 24 July 1974 ) was an English physicist and Nobel Prize winner who is best known for discovering the neutron .