Practice Passage Test - 1 | Practice Passages for MCAT PDF Download

Atoms, which serve as the fundamental components of molecules, are composed of a nucleus consisting of protons and neutrons, with electrons surrounding it. The number of protons determines the identity of an atom, while the stability and reactivity of an atom often rely on the quantities of neutrons and electrons it possesses. Nucleons, the constituents of atomic nuclei, are constructed from elementary particles called quarks. Quarks are bound together by the strong force, resulting in the formation of composite particles known as hadrons. This strong force, also referred to as the nuclear force, is responsible for holding protons and neutrons together within the nucleus, triumphing over other potentially influential forces. Baryons, a type of hadron containing three quarks, generate a charged nucleon when two up quarks and one down quark combine, while uncharged nucleons are formed when one up quark combines with two down quarks. Mesons, which belong to the hadron family, represent unstable particles comprising one quark and one antiquark.