Quarks are elementary particles and fundamental constituents of matter. They are subatomic particles that contribute most of the mass in the universe. Quarks are indivisible and cannot be broken down into smaller components. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons. All commonly observable matter is composed of up quarks, down quarks, and electrons. Quarks are observed to occur only in combinations of two. The six varieties, or “flavors,” of quark have acquired the names up, down, charm, strange, top, and bottom. Up,... Show more Quarks are elementary particles and fundamental constituents of matter. They are subatomic particles that contribute most of the mass in the universe. Quarks are indivisible and cannot be broken down into smaller components. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons. All commonly observable matter is composed of up quarks, down quarks, and electrons. Quarks are observed to occur only in combinations of two. The six varieties, or “flavors,” of quark have acquired the names up, down, charm, strange, top, and bottom. Up, charm, and top quarks have a charge of +2⁄3, while down, strange, and bottom quarks have a charge of -1⁄3. Leptons are particles of matter that are not affected by the strong force, but are only subjected to the weak forces. There are two main classes of leptons: charged leptons, and neutral leptons. Leptons can either carry one unit of electric charge or be neutral. The charged leptons are the electrons, muons, and taus. Each of these types has a negative charge and a distinct mass. Leptons are a fair bit lighter than quarks. The Big Bang is a physical theory that describes the expansion of the universe from a state of high density and temperature. The theory was first proposed in 1927 by Georges Lemaître, a Roman Catholic priest and physicist. The Big Bang theory states that the universe began as a tiny, dense fireball that exploded about 13.8 billion years ago. The early universe was too hot for atoms to exist, and as it expanded, its temperature and density decreased. Atoms formed, then molecules. The Big Bang is the best model used by astronomers to explain the creation of matter, space, and time. However, what caused the explosion is still a mystery. Related: Basic Physics Practice Test: Elementary Particles Basic Physics Practice Test: Astrophysics and Cosmology Show less
Quarks are elementary particles and fundamental constituents of matter. They are subatomic particles that contribute most of the mass in the universe. Quarks are indivisible and cannot be broken down into smaller components. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons. All commonly observable matter is composed of up quarks, down quarks, and electrons. Quarks are observed to occur only in combinations of two. The six varieties, or “flavors,” of quark have acquired the names up, down, charm, strange, top, and bottom. Up, charm, and top quarks have a charge of +2⁄3, while down, strange, and bottom quarks have a charge of -1⁄3.
Leptons are particles of matter that are not affected by the strong force, but are only subjected to the weak forces. There are two main classes of leptons: charged leptons, and neutral leptons. Leptons can either carry one unit of electric charge or be neutral. The charged leptons are the electrons, muons, and taus. Each of these types has a negative charge and a distinct mass. Leptons are a fair bit lighter than quarks.
The Big Bang is a physical theory that describes the expansion of the universe from a state of high density and temperature. The theory was first proposed in 1927 by Georges Lemaître, a Roman Catholic priest and physicist. The Big Bang theory states that the universe began as a tiny, dense fireball that exploded about 13.8 billion years ago. The early universe was too hot for atoms to exist, and as it expanded, its temperature and density decreased. Atoms formed, then molecules. The Big Bang is the best model used by astronomers to explain the creation of matter, space, and time. However, what caused the explosion is still a mystery.
Related:
Basic Physics Practice Test: Elementary Particles
Basic Physics Practice Test: Astrophysics and Cosmology
Join 4M+ learners. Unlock unlimited quizzes, wrong-answer tracking, flashcards + reminders, study guides, and 1-on-1 challenges.