Question 1

Which of the following statements best describes the quantum property spin?

Accepted Answer

A) Spin is a measure of the rotation rate of a subatomic particle. 
B) Spin is a measure of the rate at which a particle spins around (orbits)another particle. 
C) Spin is a property that applies only to large objects,like baseballs. 
D) Spin is not meant to be taken literally but measures the inherent angular momentum of a subatomic particle. 
E) Spin is not a fundamental property but rather something that can change randomly at any time. 
A) Spin is a measure of the rotation rate of a subatomic particle. 
B) Spin is a measure of the rate at which a particle spins around (orbits)another particle. 
C) Spin is a property that applies only to large objects,like baseballs. 
D) Spin is not meant to be taken literally but measures the inherent angular momentum of a subatomic particle. 
E) Spin is not a fundamental property but rather something that can change randomly at any time.

Question 2

The two families of fundamental particles out of which all ordinary matter is made are

Accepted Answer

A) protons and neutrons. 
B) leptons and quarks. 
C) electrons and neutrinos. 
D) quarks and neutrinos. 
E) leptons and photons. 
A) protons and neutrons. 
B) leptons and quarks. 
C) electrons and neutrinos. 
D) quarks and neutrinos. 
E) leptons and photons.

Question 3

The four fundamental forces are

Accepted Answer

A) strong force,weak force,electromagnetic force,gravity. 
B) strong force,weak force,electric force,magnetic force. 
C) nuclear force,electromagnetic force,gravity,tidal force. 
D) nuclear force,gravity,electric force,magnetic force. 
A) strong force,weak force,electromagnetic force,gravity. 
B) strong force,weak force,electric force,magnetic force. 
C) nuclear force,electromagnetic force,gravity,tidal force. 
D) nuclear force,gravity,electric force,magnetic force.

Question 4

What happens when a particle and its corresponding particle of antimatter meet?

Accepted Answer

A) No one knows,since antimatter is only theoretical and not known to really exist. 
B) The particles join together to make an antimatter atom. 
C) The particles collide and then bounce back apart. 
D) The particle and the antiparticle are annihilated,turning all their mass into energy. 
E) They live happily ever after. 
A) No one knows,since antimatter is only theoretical and not known to really exist. 
B) The particles join together to make an antimatter atom. 
C) The particles collide and then bounce back apart. 
D) The particle and the antiparticle are annihilated,turning all their mass into energy. 
E) They live happily ever after.

Question 5

Which of the following statements about electrons is not true?

Accepted Answer

A) Electrons carry a negative charge. 
B) In an atom,an electron can have two possible values for its spin,usually called spin up and spin down. 
C) Electrons are one of the six known types of lepton. 
D) Electrons have about the same mass as protons. 
E) Electrons are both particles and waves. 
A) Electrons carry a negative charge. 
B) In an atom,an electron can have two possible values for its spin,usually called spin up and spin down. 
C) Electrons are one of the six known types of lepton. 
D) Electrons have about the same mass as protons. 
E) Electrons are both particles and waves.

Question 6

Why is there a limit to how much compression can be counterbalanced by electron degeneracy pressure?

Accepted Answer

A) At extreme compression,the electron speeds approach the speed of light and therefore cannot increase further. 
B) At extreme compression,electrons are forced to stop moving,and once stopped there is nothing more they can do. 
C) At extreme compression,atoms are fully ionized,so electrons go free and can no longer exert pressure. 
D) The exclusion principle excludes electrons from exerting more pressure than the uncertainty principle would otherwise allow. 
E) Electrons are very small and are simply incapable of exerting much pressure. 
A) At extreme compression,the electron speeds approach the speed of light and therefore cannot increase further. 
B) At extreme compression,electrons are forced to stop moving,and once stopped there is nothing more they can do. 
C) At extreme compression,atoms are fully ionized,so electrons go free and can no longer exert pressure. 
D) The exclusion principle excludes electrons from exerting more pressure than the uncertainty principle would otherwise allow. 
E) Electrons are very small and are simply incapable of exerting much pressure.

Question 7

Which of the following is not an exchange particle (that mediates the four fundamental forces of nature)?

Accepted Answer

A) gravitons 
B) photons 
C) leptons 
D) weak bosons 
E) gluons 
A) gravitons 
B) photons 
C) leptons 
D) weak bosons 
E) gluons

Question 8

What does the exclusion principle say?

Accepted Answer

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

Question 9

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?

Accepted Answer

A) Electrons would fall into the nuclei of atoms. 
B) The nuclei of atoms would fall apart. 
C) Atoms would be immediately ionized. 
D) Nothing;atoms would be unaffected by this change. 
A) Electrons would fall into the nuclei of atoms. 
B) The nuclei of atoms would fall apart. 
C) Atoms would be immediately ionized. 
D) Nothing;atoms would be unaffected by this change.

Question 10

Briefly explain how antimatter can be produced by scientists.

Accepted Answer

Antimatter is produced in particle accel

Question 11

The force of gravity is the only one of the four forces felt on very large size scales.Which of the following best explains why the other forces don't play a major role on large scales?

Accepted Answer

A) The other three forces are all very short in range,and cannot be felt over large distances. 
B) The strong and weak forces act only on very small scales,and large objects tend to be electrically neutral and therefore don't feel an electromagnetic force. 
C) Gravity is by far the strongest force,so it simply dominates on large size scales. 
D) Effects of the strong and weak forces tend to cancel out effects of the electromagnetic force on large scales. 
A) The other three forces are all very short in range,and cannot be felt over large distances. 
B) The strong and weak forces act only on very small scales,and large objects tend to be electrically neutral and therefore don't feel an electromagnetic force. 
C) Gravity is by far the strongest force,so it simply dominates on large size scales. 
D) Effects of the strong and weak forces tend to cancel out effects of the electromagnetic force on large scales.

Question 12

Process of Science: The "standard model" that describes the building blocks of nature works extremely well and has been most recently verified through the discovery of the Higgs boson.Why,then,do some scientists continue to search for a simpler model?

Accepted Answer

This is basically Occam's razor: the sta

Question 13

Which of the following is not a fundamental force?

Accepted Answer

A) strong force 
B) weak force 
C) degeneracy pressure 
D) electromagnetic force 
E) gravity 
A) strong force 
B) weak force 
C) degeneracy pressure 
D) electromagnetic force 
E) gravity

Question 14

What is Hawking radiation?

Accepted Answer

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

Question 15

The electromagnetic force between two charged particles is much greater than the strength of gravity between them,no matter how far apart they are.Nevertheless,it is gravity,rather than the electromagnetic force,that dominates the universe on large scales.Briefly explain why.

Accepted Answer

Despite its far greater strength per par

Question 16

According to the uncertainty principle,which of the following statements is true?

Accepted Answer

A) It is impossible to measure both the mass and the momentum of a particle at the same time. 
B) It is impossible to measure both the position and the momentum of a particle at the same time. 
C) It is impossible for science to make any meaningful predictions about nature whatsoever. 
D) It is impossible to measure both the speed and direction of a particle at the same time. 
A) It is impossible to measure both the mass and the momentum of a particle at the same time. 
B) It is impossible to measure both the position and the momentum of a particle at the same time. 
C) It is impossible for science to make any meaningful predictions about nature whatsoever. 
D) It is impossible to measure both the speed and direction of a particle at the same time.

Question 17

The mass of a neutrino is

Accepted Answer

A) equal to the mass of an electron. 
B) equal to the mass of a proton. 
C) equal to the mass of a neutron. 
D) less than the mass of an electron but its actual value is unknown. 
E) zero. 
A) equal to the mass of an electron. 
B) equal to the mass of a proton. 
C) equal to the mass of a neutron. 
D) less than the mass of an electron but its actual value is unknown. 
E) zero.

Question 18

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?

Accepted Answer

A) uuu 
B) uud 
C) udd 
D) uuudd 
A) uuu 
B) uud 
C) udd 
D) uuudd

Question 19

Given that many of the ideas of quantum mechanics seem so strange to our intuition,why do scientists think these ideas are correct?

Accepted Answer

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

Question 20

The characteristic that distinguishes fermions from bosons is

Accepted Answer

A) their mass. 
B) their electric charge. 
C) their spin. 
D) their size. 
E) their speed of travel. 
A) their mass. 
B) their electric charge. 
C) their spin. 
D) their size. 
E) their speed of travel.

Exam 28: Building Blocks of the Universe

Which of the following statements best describes the quantum property spin?

The two families of fundamental particles out of which all ordinary matter is made are

The four fundamental forces are

What happens when a particle and its corresponding particle of antimatter meet?

Which of the following statements about electrons is not true?

Why is there a limit to how much compression can be counterbalanced by electron degeneracy pressure?

Which of the following is not an exchange particle (that mediates the four fundamental forces of nature)?

What does the exclusion principle say?

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?

Briefly explain how antimatter can be produced by scientists.

The force of gravity is the only one of the four forces felt on very large size scales.Which of the following best explains why the other forces don't play a major role on large scales?

Process of Science: The "standard model" that describes the building blocks of nature works extremely well and has been most recently verified through the discovery of the Higgs boson.Why,then,do some scientists continue to search for a simpler model?

Which of the following is not a fundamental force?

What is Hawking radiation?

The electromagnetic force between two charged particles is much greater than the strength of gravity between them,no matter how far apart they are.Nevertheless,it is gravity,rather than the electromagnetic force,that dominates the universe on large scales.Briefly explain why.

According to the uncertainty principle,which of the following statements is true?

The mass of a neutrino is

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?

Given that many of the ideas of quantum mechanics seem so strange to our intuition,why do scientists think these ideas are correct?

The characteristic that distinguishes fermions from bosons is

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light and Matter: Reading Messages from the Cosmos

Telescopes: Portals of Discovery

Our Planetary System

Formation of the Solar System

Planetary Geology: Earth and the Other Terrestrial Worlds

Planetary Atmospheres: Earth and the Other Terrestrial Worlds

Jovian Planet Systems

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: The New Science of Distant Worlds

Our Star

Surveying the Stars

Star Birth

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundations of Modern Cosmology

Galaxy Evolution

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Celestial Timekeeping and Navigation

Space and Time

Spacetime and Gravity

Filters