Astronomy Homework 12

The Sun is composed of about ______ and _______ plus 2% other elements. 71% helium/27% hydrogen 50% hydrogen/50% helium 71% hydrogen/27% helium 77% nitrogen/22% oxygen

71% hydrogen/27% helium

Approximately how massive is the Sun as compared to the Earth? 100 times 300 times 3,000 times 300,000 times one million times

300,000 times

The ideal gas law implies that raising the temperature and density of a gas increases the pressure of the gas. True False

True

The magnetic fields in sunspots can be detected by the fact that some lines in the spectrum of a gas split into two or more lines by the action of magnetic fields. True False

True

From the center out, the correct order of the parts of the Sun is core, convection zone, radiative zone, photosphere, chromosphere, corona. radiative zone, core, chromosphere, convection zone, photosphere, corona. core, convection zone, photosphere, chromosphere, corona, radiative zone. core, radiative zone, convection zone, photosphere, chromosphere, corona.

core, radiative zone, convection zone, photosphere, chromosphere, corona.

The solar wind is created in the Sun's _______. core radiation zone convection zone corona

corona

The solar cycle is a result of the nuclear fusion at the core of the Sun loss of energy in the Sun's magnetic field through flares, sunspots, and prominences. differential rotation of the Sun. motion in the convection zone cycling material into the Sun's core.

differential rotation of the Sun.

The diameter of the Sun is determined by measuring its ____ and _____. volume; density distance; volume distance; angular size mass; density

distance; angular size

Generally speaking, activity on the surface of the Sun is primarily driven by gravity. thermodynamics. electromagnetism. nuclear reactions.

electromagnetism.

The Sun rotates _____ at its equator than at its poles. slower the same faster

faster

The Sun's core is generating energy in the form of ________. gamma rays ultraviolet waves X-rays visible light radio waves

gamma rays

Which is denser? the Sun, which is about 300,000 times more massive than the Earth the Earth (a solid object)

the Earth (a solid object)

Which is more massive? the Sun (a gaseous giant) the Earth (a solid object)

the Sun (a gaseous giant)

What holds the Sun together? the Sun's gravity the Sun's magnetic field the pressure of the solar wind radiation pressure quantum forces

the Sun's gravity

The Sun converts mass to energy through the proton-proton chain. True False

True

The Sun rotates slower near its poles than near its equator. True False

True

The average density of the Sun is about the same as that of Jupiter. True False

True

The light produced in the Sun's core is able to pass freely through the Sun. True False

False

The mass of an entire hydrogen atom is converted into energy during the proton-proton chain. True False

False

How big is the Sun compared to the Earth, by diameter, approximately? 5 times bigger 15 times bigger 500 times bigger 100 times bigger 1,000 times bigger

100 times bigger

About how long is the solar cycle (evidenced by sunspots)? 3 years 5 days 11 years 22 years

11 years

The temperature at the Sun's core is about _____. 15,000,000 K 1,500,00 K 150,000 K 15,000 K

15,000,000 K

The Sun is about how far from Earth? 380,000 km 93,000,000 km 150,000,000 km one light-year

150,000,000 km

Approximately how long does energy take to travel from the core to the surface of the Sun? a few seconds a few minutes a thousand years 16 million years 10 billion years

16 million years

Light travels for about _____ to reach the Sun's surface from the Sun's core, and about ____ to reach the Earth from the Sun's surface. 16 million years; 8 minutes 100 years; 8 minutes 1 minute; 8 seconds 100 years; 8 seconds

16 million years; 8 minutes

About how long is the solar cycle (evidenced by the polarity of the Sun's magnetic field)? 3 years 5 days 11 years 22 years

22 years

According to the ideal gas law, the only way to have high pressure is by having a high density. True False

False

Comparison of the number of sunspots and the surface temperature of the Earth shows a correspondence right up to the present day. True False

False

Since nuclear fusion in the Sun creates energy from matter, why doesn't it violate the law of conservation of energy? TrueConservation of energy only applies to mechanical and electrical systems, not to nuclear physics. FalseThe energy actually comes from the motion of the four separate hydrogen atoms, which move less bound together as one helium atom. Matter and energy are equivalent, as expressed by Einstein's equation E = mc2. It does, but conservation of energy is only a law in Newtonian physics, which does not work under the conditions at the center of the Sun.

Matter and energy are equivalent, as expressed by Einstein's equation E = mc2.

The _____ a period _______, that coincides with _______. sunspot cycle is; of 11 years; the Sun's rotation around its axis Maunder Minimum is; of low sunspot activity; the "little ice age" in the late 17th century magnetic cycle is; of 22 years; a period of intense solar and earthquakes solar cycle is; of high sunspot activity; the cycle of the planetary alignments

Maunder Minimum is; of low sunspot activity; the "little ice age" in the late 17th century

Why are astronomers interested in detecting neutrinos from the Sun? Neutrinos can reveal the Sun's inner magnetic field. Neutrinos give information about the nuclear reactions in the Sun's core. Neutrinos allow the prediction of the sunspot cycle. Neutrinos help in predicting the occurrence of solar flares.

Neutrinos give information about the nuclear reactions in the Sun's core.

At which observatory listed below are scientists trying to capture neutrinos? SOHO (Solar & Heliospheric Observatory) Super Kamiokande, Japan GONG (Global Oscillations network group) Hubble Space Telescope

Super Kamiokande, Japan

Why does the number of sunspots change over time? The temperature of the Sun increases and decreases over time. The brightness of the Sun increases and decreases with time. The Sun's magnetic field changes in strength and shape with time. The solar wind changes speed with time, obscuring them. The number of sunspots does not change-the spots are simply on the other side.

The Sun's magnetic field changes in strength and shape with time.

How is the composition of the Sun today different than when it formed 4.6 billion years ago? There is no difference, the composition has not changed. There is now more hydrogen and less helium. There is now more helium and less hydrogen. The amount of hydrogen and helium has not changed, but the amount of heavier elements has decreased.

There is now more helium and less hydrogen.

Why do sunspots appear dark? They are made of different material than the surrounding gases. They are hotter than the surrounding gases. They are cooler than the surrounding gases. Their magnetic fields block light.

They are cooler than the surrounding gases.

Astronomers use theory to determine the temperature of the Sun's core, because they cannot measure the core temperature directly. True False

True

Coronal holes are cooler parts of the corona from which the solar wind escapes. True False

True

One method of measuring the distance between the Earth and the Sun is by bouncing radar waves off the Sun. True False

True

Seismic waves observed at the surface of the Sun provide clues about the temperature and the density of the solar interior. True False

True

Starting from the core, the internal temperatures of the Sun decreases gradually until reaching the photosphere. True False

True

A solar prominence is essentially a cloud of hot gas lifting off the surface of the Sun. an eruption of gas heated by the sudden recombination of opposite polarity parts of the Sun's magnetic field. a plasma confined to a magnetic tube sticking out of the surface of the Sun. an aurora occurring in the Sun's atmosphere instead of the Earth's.

a cloud of hot gas lifting off the surface of the Sun.

The Sun's composition by the % of mass is 71% ____, 27% _____, and 2% _____. hydrogen; oxygen; helium helium; hydrogen; other elements hydrogen; helium; other elements hydrogen; helium; carbon

hydrogen; helium; other elements

The photosphere is the part of the Sun where nuclear fusion is occurring. is the layer of the Sun where it transitions from being opaque to transparent. is the hottest part of the Sun. is the densest part of the Sun.

is the layer of the Sun where it transitions from being opaque to transparent.

The Zeeman effect, in which energy levels of electrons are shifted and produce a corresponding split in spectral lines observed, is used to measure _________ at the Sun's surface. magnetic field strength the intensity of gamma rays gravitational field strength the velocity and oscillations of gas

magnetic field strength

One way to probe the rate of nuclear reactions in the center of the Sun is by studying ______ produced because _____________. positrons; they annihilate into gamma rays of very specific energies neutrinos; they pass out of the Sun without undergoing a random walk heavy hydrogen; it has different spectral lines than normal hydrogen wave motions; they can be measured at the Sun's surface

neutrinos; they pass out of the Sun without undergoing a random walk

What powers the Sun? chemical burning of hydrogen and oxygen nuclear fusion of hydrogen into helium nuclear fission of helium into hydrogen the breakdown of neutrinos friction as it moves through the gases of space

nuclear fusion of hydrogen into helium

In the Sun, nuclear fusion occurs in the core and the radiative zone. only in the core. throughout the entire star.

only in the core.

Which part of the Sun is covered with granules? corona chromosphere photosphere core

photosphere

Sunspots are dark because they are landmasses like continents on the Earth. holes in the photosphere, allowing astronomers to view into the Sun's interior. shadows from clouds in the Sun's atmosphere. slightly cooler regions, meaning they emit less light than the surrounding areas.

slightly cooler regions, meaning they emit less light than the surrounding areas.

Although the Sun's core has a density much greater than rock it is considered a gaseous object because the Sun's high internal temperature prevent the atoms from bonding together to form a liquid or a solid. a large fraction of the Sun's interior is made of electromagnetic radiation (light). it is composed mostly of hydrogen. the Sun formed from the Solar nebula which itself was a large gas and dust cloud.

the Sun's high internal temperature prevent the atoms from bonding together to form a liquid or a solid.

The Sun's energy comes from __________. the release of magnetic energy the conversion of mass into energy its rotation slowing down meteors and asteroids striking its surface

the conversion of mass into energy

What is the Sun's outermost atmosphere called? the corona the chromosphere the photosphere the radiative zone

the corona

The Sun produces its energy through __________. the fusion of neutrinos into helium the fusion of helium into hydrogen the fusion of hydrogen into helium electric currents generated in its core gradual gravitational collapse

the fusion of hydrogen into helium

What is the visible surface of the Sun called? the corona the chromosphere the photosphere the radiative zone

the photosphere

What is the specific 3-step energy generating process in the Sun called? hydrostatic equilibrium thermography the proton-proton chain radiative transfer

the proton-proton chain

What is solar seismology? the study of the Sun's atmosphere by analyzing waves in the Sun's interior the study of the Sun's interior by analyzing waves in the Sun's atmosphere the study of gravitational waves from the Sun the study of the Sun's changing size

the study of the Sun's interior by analyzing waves in the Sun's atmosphere

Which of the following gives evidence of the solar wind? the tails of comets jet streams on Earth solar prominences solar flares sunspots

the tails of comets

The temperature at the ____ of the Sun's chromosphere is higher than the temperature _________. base; at the top of the chromosphere top; at the base of the chromosphere top; of the Sun's corona base; of the Sun's corona

top; at the base of the chromosphere

If the Sun's rotation carries two sunspots around the side out of sight, you might see them again in about twelve hours two weeks a month six months

two weeks

Astronomers know what the solar interior is like by observing the interior directly. By using the appropriate filters it is possible to reduce the bright glow of the Sun and to peer directly at the Sun's interior. constructing a miniature Sun in the laboratory and extrapolating the results to the real Sun. using locally-tested physics combined with observations to build a mathematical model of what the Sun should be like in its interior. sending probes directly into the Sun and sending back the information.

using locally-tested physics combined with observations to build a mathematical model of what the Sun should be like in its interior.