Complex sentence: Sir John Douglas Cockcroft (27 May 1897--18 September 1967) was a British physicist who shared the Nobel Prize in Physics in 1951 for splitting the atomic nucleus with Ernest Walton, and was instrumental in the development of nuclear power.
Split into simpler sentences: Sir John Douglas Cockcroft (27 May 1897--18 September 1967) was a British physicist. He shared the Nobel Prize in Physics for splitting the atomic nucleus with Ernest Walton, and was instrumental in the development of nuclear power.