ASTRO Ch. S4. Reading / Concept Quiz

Chapter S4 Reading Quiz

What is the primary topic of study in quantum mechanics? A. the role played by atoms in astronomy B. the mechanical movements of the heavens. C. subatomic particles and the forces with which they interact D. the role of relativity in astronomy

What do we mean by the spin of a subatomic particle? A. It is a measure of the particle's electrical charge. B.It is one of the basic properties of any particle and is a measure of the particle's angular momentum. C. It describes how fast the particle is rotating on its axis at a given time; if more torque is applied, the particle spins faster. D. The spin of a particle describes how the story of the particle is portrayed to journalists.

Based on their spin, all particles fall into one of the following categories ________________. A. color, flavor, and mass B. matter and antimatter C. quarks and leptons D. fermions and bosons

According to modern understanding, protons and neutrons are each composed of ______. A. four bosons B. two fermions C. three leptons D. three quarks

Which of the following is not considered a fundamental particle? A. an up quark B. a neutrino C. an electron D. a proton

Which statement about antimatter is not true? A. Every ordinary particle has a corresponding antiparticle. B. Antimatter has been hypothesized to exist but has never actually been detected. C. An antielectron (positron) is identical to an ordinary electron except it has a positive charge. D. When a particle and its antiparticle meet, the result is mutual annihilation that turns all of the mass into energy.

The four fundamental forces are __________. A. strong force, weak force, electric force, and magnetic force B. strong force, weak force, electromagnetic force, and gravity C. nuclear force, gravity, electric force, and magnetic force D. nuclear force, electromagnetic force, gravity, and tidal force

What are the two fundamental laws that lie at the heart of quantum mechanics? A. the law of conservation of angular momentum and the law of conservation of energy B. the uncertainty principle and the exclusion principle C. the law of conservation of energy and the electromagnetic force law D. the absoluteness of the speed of light and the equivalence principle

According to the uncertainty principle, which of the following statements is true? A.It is impossible to measure both the position and the momentum of a particle at the same time. B. It is impossible to measure both the mass and the momentum of a particle at the same time. C. It is impossible to measure both the speed and direction of a particle at the same time. D. It is impossible for science to make any meaningful predictions about nature whatsoever.

An alternative statement of the uncertainly principle tells us that we cannot know precisely both ______. A. a particle's mass and energy B. a particle's momentum and its energy C. a particle's energy and the time during which it has this energy D. whether a particle is a wave or whether it is truly a particle

What does the exclusion principle say? A. Two fermions cannot occupy the same quantum state at the same time. B. No two particles of any type can ever occupy the same quantum state at the same time. C. The laws of quantum mechanics are excluded from our common sense. D. If a particle has a precisely defined position it is excluded from having a precisely defined momentum.

How does degeneracy pressure differ from thermal pressure? A. Degeneracy pressure affects stars, but thermal pressure does not. B. Degeneracy pressure cannot support an object against the crush of gravity, but thermal pressure can. C. Degeneracy pressure can arise in a plasma, but thermal pressure can not. D. Degeneracy pressure continues to be felt even if an object becomes cold, but thermal pressure is drastically reduced as an object gets cold.

How is quantum tunneling important to our existence here on Earth? A. It plays a crucial role in nuclear fusion in the Sun, so that our Sun would not shine brightly without it. B. It explains how neutron stars are able to stay stable rather than collapsing under their strong gravity. C. It is important to understanding the law of conservation of energy. D. It explains why electrons in atoms gradually fill different energy levels, thus making chemistry possible.

What is Hawking radiation? A. a hypothesized way for black holes to gradually shrink in mass B. a type of radiation that we have detected so far only with infrared telescopes in space C. a type of high-energy radiation that comes from inside a black hole's event horizon D. a type of radiation coming from objects supported by degeneracy pressure

Chapter 6 Concept Quiz

Given that many of the ideas of quantum mechanics seem so strange to our intuition, why do scientists think these ideas are correct? A. Quantum ideas were expected to be strange, so the fact that they are strange only lends them support. B. Quantum ideas can be used to make precise predictions that have been tested and confirmed through observations and experiments. C. Actually, few scientists think the quantum ideas are correct, and most expect the theories of quantum mechanics to be completely replaced in the near future. D. Although the ideas seem strange at first, they make perfect sense once they are studied in depth, which is why scientists accept them.

Which of the following is not one of the basic properties by which we classify a subatomic particle? A. mass B. spin C. temperature D. charge (electrical)

The primary scientific purpose of a particle accelerator is to ______. A. make small particles go fast B. make small particles achieve large accelerations C. produce energy for commercial use D. create particles and study their behavior

Which of the following statements about electrons is not true? A. In an atom, an electron can have two possible values for its spin, usually called spin up and spin down. B. Electrons can behave both as particles and as waves. C. Electrons are one of the six known types of lepton. D. They are composed of quarks.

Recall that an up quark (u) has a charge of +2/3 and a down quark (d) has a charge of -1/3. Which of the following quark compositions describes a proton? A. uud B. udd C. uuu D. uuudd

Suppose that, through the malicious act of an eight-dimensional alien being, the strong force was suddenly turned off throughout the universe. What would happen almost immediately to atoms? A. Atoms would be immediately ionized. B. Electrons would fall into the nuclei of atoms. C. Nothing; atoms would be unaffected by this change. D. The nuclei of atoms would fall apart.

The force of gravity is the only one of the four forces felt on large size scales. Which of the following best explains why the other forces don't play a major role on large scales? A. Gravity is by far the strongest force, so it simply dominates on large size scales. B. Effects of the strong and weak forces tend to cancel out effects of the electromagnetic force on large scales. C. The strong and weak forces act only on small scales, and large objects tend to be electrically neutral and therefore don't feel an electromagnetic force. D. The other three forces are all short in range, and cannot be felt over large distances.

Does the uncertainty principle affect our ability to follow the path of a baseball? Why or why not? A. Yes, because we cannot know both where the baseball is and which way it is going at the same time. B. No, because the uncertainties in the position and momentum of the baseball are so small in comparison to its size and total momentum that they are unnoticeable. C. No, because the uncertainty principle applies only to electrons. D. No, because the exclusion principle says that large objects are excluded from the consequences of the uncertainty principle.

All the following statements are true. Which one can be attributed to the exclusion principle? A. Two electrons with the same spin cannot occupy the same energy level in an atom. B. If we know the location of an electron quite well, we will have little idea where it is going next. C. If an electron and antielectron meet, they will turn into energy through mutual annihilation. D. An electron has energy equal to its mass times the speed of light squared.

What else always happens when an electron is produced from energy in a particle accelerator? A. The electron begins moving at extremely high speed. B. The electron releases a tremendous amount of energy. C. An antielectron (positron) is also produced. D. The electron quickly becomes part of an atom.

Uh-oh, the malicious eight-dimensional alien beings are back. This time, imagine that they suddenly changed nature so that neither the uncertainty principle nor the exclusion principle applied to electrons. What would happen almost immediately to atoms? A. Atoms would annihilate each other, releasing huge amounts of energy. B. Electrons would fall into the nuclei of atoms. C. Nothing; atoms would be unaffected by this change. D. Atoms would be immediately ionized.

Why is there a limit to how much compression can be counterbalanced by electron degeneracy pressure? A. At extreme compression, electrons are forced to stop moving, and once stopped there is nothing more they can do. B. At extreme compression, the electron speeds approach the speed of light and therefore cannot increase further. C. At extreme compression, atoms are fully ionized so that electrons go free and can no longer exert pressure. D. Because electrons are small, they are simply incapable of exerting much pressure.

Which of the following best explains the hypothesized phenomenon of black hole evaporation? A. Black hole evaporation is a virtual process, meaning that it has been theorized by astrophysicists, but doesn't really occur. B. Virtual particles created near the black hole are constantly annihilating each other, causing a high temperature even if the black hole has no accretion disk. This high temperature provides escape velocity for the virtual particles, causing the entire "cloud" of virtual particles to expand away into space. C. Particles (or anti-particles) are occasionally ejected from within the event horizon, causing the black hole to lose mass. D. Particles (or anti-particles) are created by a quantum mechanical effect near, but outside, the event horizon of the black hole. The law of conservation of energy maintains that the black hole must lose energy to "pay" for the creation of this mass.

Which of the following statements about quantum tunneling is not true? A. It allows electrons and other subatomic particles to pass through wall-like energy barriers even when it seems they do not have enough energy to get through the barriers. B. Although it has been observed to occur, it violates all other known laws of nature and explaining it therefore represents a major challenge to physicists. C. It is used in modern electronics and, in fact, our modern-day computers would not work without it. D. It plays a crucial role in nuclear fusion in the Sun.