

A quark is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons.
The most stable hadrons are protons and neutrons, the components of the atomic nuclei.
According to the quark model of fundamental particles, neutrons, the neutral particles in an atoms nucleus is composed of three quarks. There are six types of quarks, known as flavours: up, down, strange, charm, top and bottom.
The neutron is composed of two down quarks and one up quark.
