Chapter 11 exam review

Which is closest to the temperature of the Sun's core? 10 million K 10,000 K 100 million K 100,000 K 1 million K

10 million K

Which of these groups of particles has the greatest mass? a helium nucleus with two protons and two neutrons four electrons four individual protons

four individual protons

Which of the following best explains why nuclear fusion requires bringing nuclei extremely close together? Nuclei have to be very hot in order to fuse, and the only way to get them hot is to bring them close together. Fusion can proceed only by the proton-proton chain, and therefore requires that protons come close enough together to be linked up into a chain. Nuclei normally repel because they are all positively charged and can be made to stick only when brought close enough for the strong force to take hold. Nuclei are attracted to each other by the electromagnetic force, but this force is only strong enough to make nuclei stick when they are very close together.

Nuclei normally repel because they are all positively charged and can be made to stick only when brought close enough for the strong force to take hold.

Which of the following is not a method astronomers use to determine the physical conditions inside the Sun? Observing X-ray images of the solar interior using satellites. Measuring Doppler shifts to observe solar vibrations. Detecting solar neutrinos generated in the Sun's core. Building mathematical models that use the laws of physics. Detecting solar neutrinos generated in the Sun's core and measuring Doppler shifts to observe solar vibrations.

Observing X-ray images of the solar interior using satellites.

Where in the Sun do fusion reactions happen? Core and radiation zone Everywhere inside the Sun Only the core

Only the core

All but one of the following statements describe why scientists doubt the solar sunspot cycle affects global climate. Identify which statement is irrelevant to the explanation. Solar winds can affect satellite communications. Variations in solar activity affect the Sun's luminosity by a very tiny amount. The solar cycle varies every 11 years; average Earth temperatures do not show an 11 year variation. The variations in solar particle winds do not change the temperature of the Earth's ocean or ground.

Solar winds can affect satellite communications.

Which of the following correctly compares the Sun's energy generation process to the energy generation process in human-built nuclear power plants? The Sun generates energy by fusing small nuclei into larger ones, while our power plants generate energy by the fission (splitting) of large nuclei. Both processes involve nuclear fusion, but the Sun fuses hydrogen while nuclear power plants fuse uranium. The Sun generates energy through nuclear reactions while nuclear power plants generate energy through chemical reactions. The Sun generates energy through fission while nuclear power plants generate energy through fusion.

The Sun generates energy by fusing small nuclei into larger ones, while our power plants generate energy by the fission (splitting) of large nuclei.

Which of the following quantities is equal to the energy per second generated by the Sun's nuclear reactions? The luminosity of the Sun's photosphere The temperature of the Sun's core The force of gravity holding the Sun together The temperature at the Sun's photosphere

The luminosity of the Sun's photosphere

Why do sunspots appear darker than their surroundings? They are cooler than their surroundings. They block some of the sunlight from the photosphere. They do not emit any light

They are cooler than their surroundings.

Why are neutrinos so difficult to detect? No one knows: this is the essence of the "solar neutrino problem." They have no mass. They are extremely rare. They have a tendency to pass through just about any material without any interactions.

They have a tendency to pass through just about any material without any interactions.

Based on its surface temperature of 6,000 K, most photons that leave the Sun's surface lie in which region of the Visible Infrared X-ray Ultraviolet Microwave

Visible

The Sun's surface seethes and churns with a bubbling pattern. Why? The churning is an illusion created by varying radiation, as the gas on the Sun's surface is actually quite still. The churning gas is being stirred up by the strong solar wind. The Sun's surface is boiling. We are seeing hot gas rising and cool gas falling due to the convection that occurs beneath the surface.

We are seeing hot gas rising and cool gas falling due to the convection that occurs beneath the surface.

Which of the following choices is not a way by which we can study the inside of the Sun? We can send a space probe into the Sun's photosphere. We can make a computer model of the Sun's interior that allow us to predict the observable properties of the Sun. We can study solar neutrinos. We can probe the interior of the Sun by studying the vibrations in its photosphere.

We can send a space probe into the Sun's photosphere.

The light radiated from the Sun's surface reaches Earth in about 8 minutes, but the energy of that light was released by fusion in the solar core about ________. three days ago one hundred years ago few hundred thousand years ago one thousand years ago

few hundred thousand years ago

At the center of the Sun, fusion converts hydrogen into plasma. radiation and elements like carbon and nitrogen. helium, energy, and neutrinos.

helium, energy, and neutrinos.

t the center of the Sun, nuclear fusion converts hydrogen into helium, gamma rays, and neutrinos. radiation and elements such as carbon and nitrogen. radioactive elements such as uranium and plutonium. hydrogen compounds such as methane. molecular hydrogen.

helium, gamma rays, and neutrinos.

Scientists estimate the central temperature of the Sun using probes that measure changes in Earth's atmosphere. mathematical models of the Sun. laboratories that create miniature versions of the Sun.

mathematical models of the Sun.

Hydrogen fusion in the Sun requires a temperature (in Kelvin) of billions of degrees. millions of degrees. trillions of degrees. thousands of degrees. any temperature, as long as gravity is strong enough.

millions of degrees.

By what process do nuclear power plants on the Earth generate energy? converting kinetic energy into electricity nuclear fission converting gravitational potential energy into electricity chemical reactions nuclear fusion

nuclear fission

By what process does the Sun generate energy? gradual expansion chemical reactions nuclear fusion gravitational contraction nuclear fission

nuclear fusion

Which of these things poses the greatest hazard to communications satellites? photons from the Sun solar magnetic fields particles from the Sun

particles from the Sun

Solar energy leaves the core of the Sun in the form of photons. rising hot gas. sound waves.

photons.

Which of the following is the phase of matter in the Sun? liquid plasma gas solid a mixture of all of the above

plasma

Suppose you try to bring two protons close together. Because of the electromagnetic force, the two protons will repel one another. attract one another. collide. join together to form a deuterium nucleus. remain stationary.

repel one another.

The light radiated from the Sun's surface reaches Earth in about 8 minutes. However, the energy of this light was released by fusion in the Sun's core about several hundred thousand years ago. several hundred years ago. several thousand years ago. 11 years ago. 8 minutes ago.

several hundred thousand years ago.