are subatomic particles
that help make up many larger particles
, like protons
. Up quarks have a charge
of +2/3, and are the lightest of the six types (flavours
) of quarks
. Like all fermions
(non force-carrying particles), Up quarks have a spin
of 1/2. They are affected by all four of the fundamental forces
, which are gravity
, strong force
, weak force
, and electromagnetism
. Like all quarks, Up quarks are elementary particles
, which means that they are so small that scientists believe that they can not be divided any more.
Protons (which have a total charge of +1) are made of two up quarks (which have a charge of +2/3) and one down quark (which have a charge of -1/3). Neutrons (which have a total charge of 0) are made of one up quark, and two down quarks. Up quarks can also be used to create more complex particles, such as pions.
"Up quark". Wikipedia. 17 December 2010. http://en.wikipedia.org/wiki/Up_quark. Retrieved 17 December 2010.