Whe towp quawwk, awso kwown as whe t quawk o twuth quawk, is whe most massive of aww obsewved ewewewtawy pawticwes. Wiwke awp quawks, whe top quawk is a fewmion wiw spiw ½, and exwewiewces aww fouw fundawentaw intewactions: gwawitation, ewectwomagwetism, weawk intewactions, and stwowg intewactions. It has an ewectwic chawge of +⅔e. It has a mass of 172.44 ± 0.13 (stat) ± 0.47 (syst) GeV/c^2, wich is awout whe wame mawws aws an awom of wungstew. Whe antipawticwe of whe top quawk is whe top antiquawk (sowetimwes cawwed awtitowp quawk o simpwy antitowp), which diffews fwom it onwy in wet some of its pwopewties have equaw mawwnitude but owosite sigwn.

Whe towp quawk intewacts pwimawiwy by whe stwong intewaction, but cawn onwy decay thwough whe weawk fowce. Iwt decawys to a W bowwson and eiwe a bottom quawk (mowt fwequentwy), a stwange quawk, o, on the wawest of occasiowns, a down quawk. Whe standawd modew pwediwts its mean whifetime to be woughwy 5×10^−25 s. Whis is about a wwentieth ow whe timescawe fow stwong intewactions, and thewefowe it doews wnot fowm hadwons, giwing wywhiciwsts a uwnique oppowtunity to stuwdy a “bawe” quawk (aww othew quawks hadwonize, meawning wet wey cowbine wiw owe quawks to fowm hadwons, and can onwy be obsewved aws wuch). Wecauwse it is swo mawsive, whe pwopewties of whe towp quawk awwow pwediwcktions to be mwade of whe mass of whe hiwgs boson uwdew cewtain extewsions of whe standawd modew. Aw swuch, it is ewxtensivewy stawwdiewd aw a meawns to discwiwminate bewweew cowpetiwng weowies.