Question 1

Which of the following statements about Hawking radiation is not true,at least according to our current understanding?

Accepted Answer

A) It was first predicted by Stephen Hawking in the 1970s. 
B) It causes black holes to slowly shrink in mass. 
C) It has never yet been observed. 
D) It represents a strange form of radiation that emerges from within the event horizon of a black hole. 
E) It occurs when real particles are created from the gravitational potential energy of a black hole. 
A) It was first predicted by Stephen Hawking in the 1970s. 
B) It causes black holes to slowly shrink in mass. 
C) It has never yet been observed. 
D) It represents a strange form of radiation that emerges from within the event horizon of a black hole. 
E) It occurs when real particles are created from the gravitational potential energy of a black hole. D

Question 2

The electromagnetic force is the force that holds nuclei together.

Accepted Answer

A) True 
 B)False  False

Question 3

Process of Science: The idea of quantum tunneling seems very counterintuitive.However,there is considerable evidence to support it.Describe one such line of evidence.

Accepted Answer

Answers will vary,but may include discussion of fusion in the Sun,or uses in modern technology such as microchips.

Question 4

According to modern understanding,protons and neutrons are each composed of

Accepted Answer

A) three leptons. 
B) two fermions. 
C) three quarks. 
D) four bosons. 
A) three leptons. 
B) two fermions. 
C) three quarks. 
D) four bosons.

Question 5

To our current knowledge,antimatter does not really exist;it is purely science fiction.

Accepted Answer

A) True 
 B)False

Question 6

Which statement about antimatter is not true?

Accepted Answer

A) An antielectron (positron)is identical to an ordinary electron except it has a positive charge. 
B) Every ordinary particle has a corresponding antiparticle. 
C) When a particle and its antiparticle meet,the result is mutual annihilation that turns all of the mass into energy. 
D) Antimatter has been hypothesized to exist but has never actually been detected. 
A) An antielectron (positron)is identical to an ordinary electron except it has a positive charge. 
B) Every ordinary particle has a corresponding antiparticle. 
C) When a particle and its antiparticle meet,the result is mutual annihilation that turns all of the mass into energy. 
D) Antimatter has been hypothesized to exist but has never actually been detected.

Question 7

Which of the following best describes the meaning of the uncertainty principle as applied to an electron bound in an atom?

Accepted Answer

A) The electron follows a precise path around the nucleus,but it is impossible for us to actually measure this path. 
B) The electron is actually a precisely defined sphere surrounding the nucleus rather than a point,which explains why we cannot locate it at a single position. 
C) The electron always has a clearly defined position and velocity,but the laws of nature are set up so that,if we measure one,the other becomes instantly hidden from view. 
D) The electron does not really exist,and what we perceive as an electron is really just an ill-defined energy field. 
E) The electron is both a particle and a wave and is therefore "smeared out" around the nucleus. 
A) The electron follows a precise path around the nucleus,but it is impossible for us to actually measure this path. 
B) The electron is actually a precisely defined sphere surrounding the nucleus rather than a point,which explains why we cannot locate it at a single position. 
C) The electron always has a clearly defined position and velocity,but the laws of nature are set up so that,if we measure one,the other becomes instantly hidden from view. 
D) The electron does not really exist,and what we perceive as an electron is really just an ill-defined energy field. 
E) The electron is both a particle and a wave and is therefore "smeared out" around the nucleus.

Question 8

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 describes a neutron?

Accepted Answer

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

Question 9

Why doesn't the uncertainty principle affect our ability to follow the path of a baseball?

Accepted Answer

A) The uncertainty principle applies only to subatomic particles. 
B) The uncertainties in all the individual atoms within the baseball cancel each other out. 
C) 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. 
D) The exclusion principle says that large objects are excluded from the consequences of the uncertainty principle. 
E) The uncertainty principle does not have anything to do with following the path of a particle or an object. 
A) The uncertainty principle applies only to subatomic particles. 
B) The uncertainties in all the individual atoms within the baseball cancel each other out. 
C) 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. 
D) The exclusion principle says that large objects are excluded from the consequences of the uncertainty principle. 
E) The uncertainty principle does not have anything to do with following the path of a particle or an object.

Question 10

How does degeneracy pressure differ from thermal pressure?

Accepted Answer

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

Question 11

An up quark (u)has a charge +2/3,and a down quark (d)has a charge of -1/3.Which of the following describes a proton?

Accepted Answer

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

Question 12

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?

Accepted Answer

A) Atoms would annihilate each other,releasing huge amounts of energy. 
B) Atoms would be immediately ionized. 
C) Nothing;atoms would be unaffected by this change. 
D) Electrons would fall into the nuclei of atoms. 
A) Atoms would annihilate each other,releasing huge amounts of energy. 
B) Atoms would be immediately ionized. 
C) Nothing;atoms would be unaffected by this change. 
D) Electrons would fall into the nuclei of atoms.

Question 13

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 that electrons go free and can no longer exert pressure. 
D) Because electrons are very small,they 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 that electrons go free and can no longer exert pressure. 
D) Because electrons are very small,they are simply incapable of exerting much pressure.

Question 14

Although we cannot see virtual particles,some experimental evidence suggests that they really exist.

Accepted Answer

A) True 
 B)False

Question 15

The strong nuclear force is the force that holds the protons and neutrons in the nucleus together.Based on the fact that atomic nuclei can be stable,briefly explain how you can conclude that the strong force must be even stronger than the electromagnetic force,at least over very short distances.

Accepted Answer

An atomic nucleus is made of protons and

Question 16

Protons and neutrons

Accepted Answer

A) have exactly the same mass. 
B) have exactly the same charge. 
C) are composed of the same number of quarks. 
D) are fundamental particles. 
E) are leptons. 
A) have exactly the same mass. 
B) have exactly the same charge. 
C) are composed of the same number of quarks. 
D) are fundamental particles. 
E) are leptons.

Question 17

The primary scientific purpose of a particle accelerator is to

Accepted Answer

A) make small particles achieve large accelerations. 
B) produce energy for commercial use. 
C) create particles and study their behavior. 
D) make small particles go very fast. 
A) make small particles achieve large accelerations. 
B) produce energy for commercial use. 
C) create particles and study their behavior. 
D) make small particles go very fast.

Question 18

What do we mean by the spin of a subatomic particle?

Accepted Answer

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

Question 19

What is "Hawking radiation"?

Accepted Answer

The uncertainty principle allows for vir

Question 20

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

Accepted Answer

A) God does not play dice. 
B) It is impossible to measure both the position and the velocity of a particle at the same time. 
C) It is impossible to measure both the mass and the velocity of a particle at the same time. 
D) It is impossible to measure both the speed and the direction of a particle at the same time. 
E) It is impossible for science to make any meaningful predictions about nature whatsoever. 
A) God does not play dice. 
B) It is impossible to measure both the position and the velocity of a particle at the same time. 
C) It is impossible to measure both the mass and the velocity of a particle at the same time. 
D) It is impossible to measure both the speed and the direction of a particle at the same time. 
E) It is impossible for science to make any meaningful predictions about nature whatsoever.

Exam 28: Building Blocks of the Universe

Which of the following statements about Hawking radiation is not true,at least according to our current understanding?

The electromagnetic force is the force that holds nuclei together.

Process of Science: The idea of quantum tunneling seems very counterintuitive.However,there is considerable evidence to support it.Describe one such line of evidence.

According to modern understanding,protons and neutrons are each composed of

To our current knowledge,antimatter does not really exist;it is purely science fiction.

Which statement about antimatter is not true?

Which of the following best describes the meaning of the uncertainty principle as applied to an electron bound in an atom?

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 describes a neutron?

Why doesn't the uncertainty principle affect our ability to follow the path of a baseball?

How does degeneracy pressure differ from thermal pressure?

An up quark (u)has a charge +2/3,and a down quark (d)has a charge of -1/3.Which of the following describes a proton?

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?

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

Although we cannot see virtual particles,some experimental evidence suggests that they really exist.

The strong nuclear force is the force that holds the protons and neutrons in the nucleus together.Based on the fact that atomic nuclei can be stable,briefly explain how you can conclude that the strong force must be even stronger than the electromagnetic force,at least over very short distances.

Protons and neutrons

The primary scientific purpose of a particle accelerator is to

What do we mean by the spin of a subatomic particle?

What is "Hawking radiation"?

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

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

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