Devender

As we know from high school science class, atom consists of a nucleus comprised of neutrons and protons and nucleus is surrounded by electrons. But what are protons, neutrons and electrons made of? Proton is made of two types of elementary particles: one "down quark" and two "up quark". There are six types of quarks. Whereas, neutron is also made of quarks but from two "down quark" and one "up quark". Charge of "up quark" is positive 2/3rd of electron where for "down quark" it's negative 1/3rd of electron. And hence protons are positive and neutrons are neutral. Quarks can not exist as individual particles like electron does, and always found in combination known as hadrons. Protons and neutrons are hadrons. Quarks, are help together by strong interaction via exchange of gluons. Now hadrons can interact with each other by exchanging mesons. And due to this interaction between hadrons via mesons we have protons and neu