Chapter 11 Reading Quiz – Flashcards

According to modern science, approximately how old is the Sun? a.) 400 million years. b.) 4 1/2 billion years c.) 10,000 years d.) 25 million years

The Sun will exhaust its nuclear fuel in about ______. a.) 5000 AD b.) 50 billion years c.) 5 million years d.) 5 billion years

Which of the following correctly describes how the process of gravitational contraction can make a star hot? a.) Gravitational contraction involves the generation of heat by chemical reactions, much like the burning of coal. b.) Heat is generated when gravity contracts, because gravity is an inverse square law force. c.) Gravitational contraction involves nuclear fusion, which generates a lot of heat. d.) When a star contracts in size, gravitational potential energy is converted to thermal energy.

The source of energy that keeps the Sun shining today is _________. a.) chemical reactions b.) nuclear fission c.) nuclear fusion d.) gravitational contraction

What two physical processes balance each other to create the condition known as gravitational equilibrium in stars? a.) the strong force and the weak force b.) gravitational force and outward pressure c.) gravitational force and surface tension d.) the strong force and the electromagnetic force

Energy balance in the Sun refers to a balance between _________. a.) the rate at which fusion generates energy in the Sun's core and the rate at which the Sun's surface radiates energy into space b.) the mass that the Sun loses each second and the amount of mass converted into energy each second c.) the amount of energy the Sun radiates into space and the amount of energy that reaches Earth d.) the force of gravity pulling inward and the force due to pressure pushing outward

When we say that the Sun is a ball of plasma, we mean that _________. a.) the Sun is made of atoms and molecules b.) the Sun is roughly the same color as blood c.) the Sun consists of gas in which many or most of the atoms are ionized (missing electrons) d.) the Sun is made of material that acts like a liquid acts on Earth

What is the Sun made of (by mass)? a.) 90% dark matter, 10% ordinary matter b.) 50% hydrogen, 25% helium, 25% other elements c.) 70% hydrogen, 28% helium, 2% other elements d.) 100% hydrogen and helium

From center outward, which of the following lists the "layers" of the Sun in the correct order? a.) Core, radiation zone, convection zone, corona, chromosphere, photosphere b.) Core, radiation zone, convection zone, photosphere, chromosphere, corona c.) Core, convection zone, radiation zone, corona, chromosphere, photosphere d.) Core, corona, radiation zone, convection zone, photosphere, chromosphere

What are the appropriate units for the Sun's luminosity? a.) joules b.) newtons c.) watts d.) kilograms

The Sun's surface, as we see it with our eyes, is called the _________. a.) photosphere b.) corona c.) chromosphere d.) core

The Sun's average surface (photosphere) temperature is about ______. a.) 1,000 K b.) 5,800 K c.) 37,000 K d.) 1,000,000 K

What is the solar wind? a.) the strong wind that blows sunspots around on the surface of the Sun b.) the uppermost layer of the Sun, lying just above the corona c.) the wind that causes huge arcs of gas to rise above the Sun's surface d.) a stream of charged particles flowing outward from the surface of the Sun

The fundamental nuclear reaction occurring in the core of the Sun is _________. a.) nuclear fusion of hydrogen into helium b.) nuclear fission c.) nuclear fusion of helium to carbon d.)radioactive decay

The proton-proton chain is _________. a.) another name for the force that holds protons together in atomic nuclei b.) the linkage of numerous protons into long chains c.) an alternative way of generating energy that is different from the fusion of hydrogen into helium d.) the specific set of nuclear reactions through which the Sun fuses hydrogen into helium

The overall result of the proton-proton chain is: a.) Individual protons are joined into long chains of protons b.) 6 H becomes 1 He + energy c.) 4 H becomes 1 He + energy d.) p + p becomes 2H + energy

To estimate the central temperature of the Sun, scientists _________. a.) use hot gas to create a small Sun in a laboratory b.) monitor changes in Earth's atmosphere c.) send probes to measure the temperature d.) use computer models to predict interior conditions

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

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 _________. a.) one thousand years ago b.) a few hundred thousand years ago c.) three days ago d.) one hundred years ago

What happens to energy in the Sun's convection zone? a.) Energy is produced in the convection zone by thermal radiation. b.) Energy is produced in the convection zone by nuclear fusion. c.) Energy slowly leaks outward through the radiative diffusion of photons that repeatedly bounce off ions and electrons. d.) Energy is transported outward by the rising of hot plasma and sinking of cooler plasma.

What do sunspots, solar prominences, and solar flares all have in common? a.) They all occur only in the Sun's photosphere. b.) They are all shaped by the solar wind. c.) They are all strongly influenced by magnetic fields on the Sun. d.) They all have about the same temperature.

Which of the following is not a characteristic of the 11-year sunspot cycle? a.) The likelihood of seeing solar prominences or solar flares is higher when sunspots are more common and lower when they are less common. b.) The number of sunspots on the Sun at any one time gradually rises and falls, with an average of 11 years between the times when sunspots are most numerous. c.) The Sun's entire magnetic field flip-flops with each cycle, so that the overall magnetic cycle averages 22 years. d.) The sunspot cycle is very steady, so that each 11-year cycle is nearly identical to every other 11-year cycle.

How is the sunspot cycle directly relevant to us here on Earth? a.) The brightening and darkening of the Sun that occurs during the sunspot cycle affects plant photosynthesis here on Earth. b.) Coronal mass ejections and other activity associated with the sunspot cycle can disrupt radio communications and knock out sensitive electronic equipment. c.) The sunspot cycle is the cause of global warming. d.) The Sun's magnetic field, which plays a major role in the sunspot cycle, affects compass needles that we use on Earth. e.) The sunspot cycle strongly influences Earth's weather.