Thomson began experimenting with contact electrification and soon published his first scientific paper. In 1870, he was admitted to Owens College in Manchester (now University of Manchester) at the unusually young age of 14 and came under the influence of Balfour Stewart, Professor of Physics, who initiated Thomson into physical research. His early education was in small private schools where he demonstrated outstanding talent and interest in science. Thomson was a reserved yet devout Anglican.

He had a brother, Frederick Vernon Thomson, who was two years younger than he was. His father, Joseph James Thomson, ran an antiquarian bookshop founded by Thomson's great-grandfather. His mother, Emma Swindells, came from a local textile family. Joseph John Thomson was born on 18 December 1856 in Cheetham Hill, Manchester, Lancashire, England. Only Arnold Sommerfeld's record of mentorship offers a comparable list of high-achieving students. Thomson was also a teacher, and seven of his students went on to win Nobel Prizes: Ernest Rutherford (Chemistry 1908), Lawrence Bragg (Physics 1915), Charles Barkla (Physics 1917), Francis Aston (Chemistry 1922), Charles Thomson Rees Wilson (Physics 1927), Owen Richardson (Physics 1928) and Edward Victor Appleton (Physics 1947).

Thomson was awarded the 1906 Nobel Prize in Physics for his work on the conduction of electricity in gases. His experiments to determine the nature of positively charged particles, with Francis William Aston, were the first use of mass spectrometry and led to the development of the mass spectrograph. Thomson is also credited with finding the first evidence for isotopes of a stable (non-radioactive) element in 1913, as part of his exploration into the composition of canal rays (positive ions). In 1897, Thomson showed that cathode rays were composed of previously unknown negatively charged particles (now called electrons), which he calculated must have bodies much smaller than atoms and a very large charge-to-mass ratio. Sir Joseph John Thomson OM FRS (18 December 1856 – 30 August 1940) was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be found.

Thomson's atomic theory