Category is physics and the clue wanted to know the names of 2 particles discovered in the 20th century one with a positive charge whose names differed by one letter
answer is proton and photon
physics
The Final Jeopardy category for June 29 2010 was Physics
The Final Jeopardy category for July 29 2010 was Super Bowl
The following are the Jeopardy Final Categories for the June weekday episodes: June 1 2010 The U.S. Military June 2 2010 Historical Phases June 3 2010 Film History June 4 2010 American Politicians June 7 2010 Meteorology June 8 2010 U.S. Military History June 9 2010 Artists June 10 2010 Short Stories June 11 2010 Flags and Banners June 14 2010 Moons and Mythology June 15 2010 The 50 States June 16 2010 Modern Materials June 17 2010 Americana June 18 2010 Sports Venues June 21 2010 After the Presidency June 22 2010 Billboard Hot 100 History June 23 2010 Historic Dates June 24 2010 National Parks June 25 2010 Literature and Music June 28 2010 Botanical Etymology June 29 2010 Physics June 30 2010 Russian Composers
The Final Jeopardy category for September 17 2010 was Rivers
Pro SportsThe Final Category for January 29 2010 was Pro Sports
The June 29 2010 Jeopardy game was won by Steven Milton from San Diego, California who became a new champion with a score of $26,700
It varies with the year in 2010 on April 29 The final Jeopardy Category was Poets on Poets
The final category is The Civil War and the answer is Austin and Tallahassee
19th Century LiteratureThe final Category was 19th Century LiteratureFor Sony Rewards PlayersFits Like a Glove is the answer to March 29 2010 bonus round on Wheel of Fortune.
The Final Category was Pro Sports The clue was: The official address of the Atlanta Braves is No. 755 on the drive named for this man The answer was: Who was Hank Aaron
Jeopardy - 1984 27-29 was released on: USA: 21 October 2010
June 29 2010 was a Tuesday.