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Science Unit 1

Total questions: 148

Worksheet time: 1hrs 14mins

Name
Class
Date
1.

What does the Big Bang Theory propose about the early state of all matter and energy in the universe?

a)

Spread thin across vast empty space

b)

Compressed into an incredibly small dense point

c)

Flowing in rings around early galaxies

d)

Trapped inside giant early black holes

2.

About how long ago did the Big Bang occur?

a)

9.8 billion years ago

b)

13.8 billion years ago

c)

20.1 billion years ago

d)

4.6 billion years ago

3.

As the universe expanded and cooled after the Big Bang, what formed first that led to atoms and elements?

a)

Massive stars and galaxies

b)

Subatomic particles began to form

c)

Molecules of water condensed

d)

Large planets and moons appeared

4.

Which statement best describes the current behavior of the universe?

a)

The universe is contracting overall

b)

The universe is expanding overall

c)

The universe is static and unchanging

d)

The universe rotates around one center

5.

According to observations, what is the primary composition of matter found in stars and interstellar gases?

a)

Mostly nitrogen with traces of neon

b)

Equal parts hydrogen, helium, and silicon

c)

Three quarters hydrogen, one quarter helium

d)

Mostly carbon and oxygen

6.

Which evidence supports that distant galaxies are moving away from us?

a)

Blue shift in starlight indicates approach

b)

Red shift in light due to expansion

c)

Increased brightness from closer distance

d)

Constant color showing no motion

7.

What does cosmic microwave background radiation represent?

a)

Leftover radiation from the Big Bang

b)

Heat from nearby forming stars

c)

Signals emitted by modern galaxies

d)

Light scattered by interstellar dust

8.

Which reasoning best connects redshift to an expanding universe?

a)

Compressed waves decrease frequency

b)

Stretched light waves increase wavelength

c)

Constant wavelengths show fixed distances

d)

Shorter wavelengths mean galaxies slow down

9.

Which pair of elements would you expect to have distinct emission lines at different wavelengths in stellar spectra?

a)

Hydrogen and helium lines are identical

b)

Carbon and oxygen lines differ

c)

Nitrogen and silicon lines match exactly

d)

All elements share the same lines

10.

Which conclusion aligns with the Big Bang Theory and observed composition of the universe?

a)

Expansion stopped shortly after the first billion years

b)

Early universe produced mostly heavy metals

c)

Initial elements formed were mainly hydrogen and helium

d)

Galaxies formed before any subatomic particles

11.

Which layer is described as the visible surface of the Sun?

a)

Chromosphere layer above photosphere

b)

Photosphere the visible surface

c)

Corona the outer atmosphere

d)

Transition region separating layers

12.

In which Sun layer are thermonuclear reactions generating energy?

a)

Convective zone moving plasma

b)

Core where energy is generated

c)

Corona extending into space

d)

Radiative zone diffusing energy

13.

What process mainly carries the Sun’s energy through empty space to Earth?

a)

Conduction through solid matter

b)

Convection within fluids

c)

Radiation as electromagnetic waves

d)

Evaporation of atmospheric water

14.

According to the spectrum diagram, which has higher energy: ultraviolet or infrared?

a)

Both have equal energy levels

b)

Infrared on longer wavelength side

c)

Ultraviolet on higher frequency side

d)

Microwaves between both bands

15.

Which statement best describes the convective zone in the Sun?

a)

Energy diffuses slowly through plasma

b)

Thin layer separates cooler region

c)

Rapid heating creates gas currents

d)

Outer atmosphere extends into space

16.

Which region separates the relatively cool chromosphere from the hotter corona?

a)

Transition region thin irregular layer

b)

Radiative zone near the core

c)

Photosphere visible bright surface

d)

Convective zone upper interior

17.

Which band lies within the visible spectrum between blue and red?

a)

X‑rays just beyond ultraviolet

b)

Ultraviolet shorter than violet

c)

Green located between blue and yellow

d)

Microwaves longer than infrared

18.

As wavelength increases along the spectrum arrow, what happens to frequency?

a)

Frequency fluctuates unpredictably

b)

Frequency stays approximately constant

c)

Frequency increases accordingly

d)

Frequency decreases accordingly

19.

What happens to a heated fluid’s density in convection?

a)

Density increases so fluid sinks

b)

Density decreases so fluid sinks

c)

Density increases so fluid rises

d)

Density decreases so fluid rises

20.

Which is the Sun’s outer atmosphere extending millions of kilometers?

a)

Chromosphere lower solar atmosphere

b)

Corona outer atmosphere extending far

c)

Photosphere visible bright layer

d)

Core central energy generation zone

21.

Which statement best describes radiation in space contexts?

a)

Energy transfer by direct contact of matter

b)

Emission of energy as waves or moving particles

c)

Movement of heat only through solid materials

d)

Exchange of energy requiring a physical medium

22.

What event can temporarily increase the Sun’s radiation output?

a)

Seasonal axial tilt variations

b)

Comet impacts into the Sun

c)

Tidal forces from the Moon

d)

Sudden solar flares eruptions

23.

What cycle causes periodic changes in the Sun’s magnetic field and radiation output?

a)

5-year aurora cycle

b)

100-year eclipse cycle

c)

27-day rotation cycle

d)

11-year sunspot cycle

24.

Why can changes in the Sun’s radiation output impact Earth’s climate and space weather?

a)

Radiation variations alter atmospheric energy balance

b)

Clouds block all incoming solar radiation

c)

Earth’s core directly absorbs solar particles

d)

The Moon amplifies solar energy to Earth

25.

Which process powers stars like the Sun by forming helium from hydrogen?

a)

Radioactive decay reactions

b)

Chemical combustion of gases

c)

Nuclear fusion combining light nuclei

d)

Gravitational collapse alone

26.

How does a star’s mass generally affect its life cycle?

a)

Low-mass stars explode as frequent supernovae

b)

All stars follow identical lifespans and endings

c)

High-mass stars burn cooler and live longer

d)

High-mass stars burn hotter and die sooner

27.

Which sequence reflects the life path of a Sun-like star?

a)

Protostar to red giant to white dwarf

b)

Red supergiant to supernova to black hole

c)

Planetary nebula to low-mass star to protostar

d)

Neutron star to protostar to red dwarf

28.

In massive stars, which end-of-life outcomes are shown in the diagram?

a)

Gradual cooling into red dwarf

b)

Supernova leading to neutron star or black hole

c)

White dwarf without collapse

d)

Planetary nebula formation only

29.

What is nucleosynthesis in stars?

a)

Breaking heavy elements into lighter ones only

b)

Chemical bonding of atoms without fusion

c)

Cooling of gases to form star dust

d)

Creation of new elements via nuclear reactions

30.

Why do stars shine according to the description of nucleosynthesis?

a)

Light reflected from nearby planets

b)

Electrical sparks in the atmosphere

c)

Friction between orbiting asteroids

d)

Energy released by fusion reactions

31.

Which star color indicates the highest surface temperature?

a)

Orange light stars appear hottest

b)

Yellow light stars appear hottest

c)

Red light stars appear hottest

d)

Blue light stars appear hottest

32.

On an H–R diagram, what does the x-axis primarily represent for stars?

a)

Surface temperature and color

b)

Distance and parallax

c)

Luminosity and brightness

d)

Mass and composition

33.

Which statement best describes main sequence stars on the H–R diagram?

a)

They lie entirely off the plotted curve

b)

They follow a temperature–luminosity trend

c)

They cluster only at low luminosity

d)

They show no relation to temperature

34.

Why are many hot main sequence stars more luminous than cooler ones?

a)

Hotter stars have less mass than cooler ones

b)

Hotter stars emit more energy overall

c)

Hotter stars are always closer to Earth

d)

Hotter stars reflect more sunlight

35.

Which pair correctly contrasts red giants and white dwarfs?

a)

Giants cool but bright; dwarfs hot but dim

b)

Giants hot but dim; dwarfs cool but bright

c)

Giants small and dense; dwarfs huge and diffuse

d)

Giants blue and short-lived; dwarfs red and massive

36.

What mainly makes red giants appear bright despite cooler temperatures?

a)

They rotate faster than other stars

b)

They burn heavier elements constantly

c)

Their strong magnetic fields glow

d)

Their huge radii increase total light

37.

Which statement about white dwarfs is accurate?

a)

They are hot but have tiny radii

b)

They are cool with enormous radii

c)

They are cold and highly luminous

d)

They are blue giants on the main sequence

38.

Why do blue stars tend to have shorter lifespans?

a)

They use fuel quickly due to high mass

b)

They cool rapidly and freeze solid

c)

They lose mass by turning into planets

d)

They receive less energy from nearby stars

39.

A star moves from blue to red over time on the H–R diagram. What does this change primarily indicate?

a)

Its chemical elements disappear

b)

Its magnetic field strengthens

c)

Its distance from Earth increases

d)

Its surface temperature decreases

40.

Which reasoning best explains why many stars fall along the main sequence curve?

a)

Hydrogen fusion rate links temperature and luminosity

b)

Random placement produces a visible band

c)

Gravitational lensing draws stars onto a line

d)

Interstellar dust pushes stars into clusters

41.

Which observation supports that galaxies are moving away from Earth?

a)

Shorter wavelengths in galaxy spectra

b)

Longer wavelengths in galaxy spectra

c)

Constant wavelengths in galaxy spectra

d)

Random shifts in galaxy spectra

42.

What does the Cosmic Microwave Background indicate about the early universe?

a)

It was sparse and fragmented

b)

It was cool and irregular

c)

It was hot, dense, and uniform

d)

It was always cold and empty

43.

According to Hubble’s Law, what trend is observed among distant galaxies?

a)

Closer galaxies move faster away

b)

Farther galaxies move slower away

c)

All galaxies move at same speed

d)

Farther galaxies move faster away

44.

Which tool is used to measure redshift in starlight?

a)

Barometers for space pressure

b)

Seismometers for starquakes

c)

Spectrometers for spectra

d)

Thermometers for stellar heat

45.

Why does fusion inside stars release energy up to iron?

a)

Iron splits and releases energy

b)

Iron atoms emit heat spontaneously

c)

Fusion to iron releases stored energy

d)

Fusion to iron requires energy input

46.

Why does fusion stop at iron in high-mass stars?

a)

Iron fusion produces too much heat

b)

Iron fusion absorbs energy instead

c)

Iron fusion speeds core rotation

d)

Iron fusion increases star brightness

47.

What event spreads elements heavier than iron into space?

a)

Planetary nebula expansion

b)

White dwarf cooling

c)

Supernova explosions

d)

Red giant pulsations

48.

How do spectral absorption lines help identify elements in stars?

a)

They show unique dark wavelength gaps

b)

They show uniform bright color bands

c)

They show random flicker patterns

d)

They show continuous smooth spectra

49.

If a star’s spectral lines shift toward red, what does that indicate?

a)

The star is moving closer

b)

The star is moving away

c)

The star is rotating faster

d)

The star has cooled recently

50.

What is the key difference between absorption and emission spectra?

a)

Absorption shows bright lines; emission dark

b)

Absorption shows dark lines; emission bright

c)

Both show only continuous spectra

d)

Both show identical line patterns

51.

Which non-visible electromagnetic wave can reveal stars hidden behind dust?

a)

Microwave waves behind dust clouds

b)

Ultraviolet waves behind dust clouds

c)

Infrared waves behind dust clouds

d)

Radio waves behind dust clouds

52.

What do X-rays often help astronomers detect in space?

a)

Planetary atmospheres

b)

Solar wind directions

c)

Black holes or explosions

d)

Comet ice composition

53.

Why do some observations require space telescopes?

a)

To avoid atmospheric blocking

b)

To avoid telescope mirrors

c)

To avoid star light colors

d)

To avoid lunar phases

54.

On the H–R diagram, what does a star’s blue color indicate about surface temperature?

a)

Blue means cool temperature

b)

Blue means changing temperature

c)

Blue means hot temperature

d)

Blue means medium temperature

55.

Along the main sequence, how do hotter stars compare in luminosity?

a)

Hotter stars are invisible

b)

Hotter stars are more luminous

c)

Hotter stars are less luminous

d)

Hotter stars have same luminosity

56.

Which description fits red giants compared to white dwarfs?

a)

Hot but dim, huge radius

b)

Hot but bright, tiny radius

c)

Cool but bright, huge radius

d)

Cool but dim, tiny radius

57.

Why do blue stars have shorter lifespans?

a)

They have low temperature

b)

They have small mass

c)

They burn fuel slowly

d)

They burn fuel quickly

58.

In fusion experiments, what does a value above breakeven on an energy graph mean?

a)

No energy measured

b)

Output equals the input

c)

Input higher than output

d)

Output higher than input

59.

What process powers stars and is attempted in Earth laboratories?

a)

Combustion of gases

b)

Fission of heavy elements

c)

Fusion of light elements

d)

Radioactive decay

60.

Which statement best describes atmospheric transparency across wavelengths?

a)

Visible passes easily; infrared absorbed

b)

Infrared passes easily; visible absorbed

c)

UV passes easily; visible absorbed

d)

All wavelengths pass equally

61.

What does the trend in Figure 1 suggest about the structure of the universe?

a)

Galaxies farther away are older than nearby galaxies

b)

The universe is static and unchanging

c)

Galaxies are orbiting around a central point

d)

The universe is expanding outward in all directions

62.

Which observation most directly supports the idea that galaxies are moving away from Earth?

a)

The mass of each galaxy

b)

Redshifted light from distant galaxies

c)

High surface temperatures of galaxies

d)

Blue-shifted starlight

63.

The Cosmic Microwave Background Radiation provides evidence for the Big Bang because:

a)

It forms patterns around galaxies

b)

It shows that galaxies are accelerating

c)

It changes with the seasons

d)

It’s uniform in all directions and matches models of an early hot universe

64.

Short Constructed Response: Explain how the redshift of galaxies is used as evidence for the expansion of the universe. Use the terms “wavelength” and “motion” in your response.

a)

Redshift means color changes as stars rotate around a center

b)

Redshift means wavelengths shorten as galaxies move toward us

c)

Redshift means wavelengths lengthen as galaxies move away from us

d)

Redshift means energy increases as galaxies slow down

65.

According to Hubble’s Law described, how does the speed of a galaxy’s recession relate to its distance?

a)

Speed decreases as distance increases

b)

Speed increases as distance increases

c)

Speed stays constant regardless of distance

d)

Speed varies randomly with distance

66.

What does the nearly uniform temperature of the Cosmic Microwave Background imply?

a)

The universe stopped expanding billions of years ago

b)

Stars emit microwaves that heat surrounding space

c)

Radiation is left over from an early hot, dense universe

d)

Space is colder near galaxies than between them

67.

Which statement best describes the pattern astronomers observed for distant galaxies?

a)

Galaxies spin faster the closer they are to Earth

b)

Farther galaxies appear to move away faster than nearer ones

c)

Nearer galaxies move away faster than distant ones

d)

All galaxies move at identical speeds in any direction

68.

In the graph "Galaxy Distance vs. Recessional Velocity," what does the slope of the line represent?

a)

Temperature of interstellar space

b)

Average mass of galaxies

c)

Rate of expansion of the universe

d)

Age of the oldest galaxies

69.

Why is the Cosmic Microwave Background detected from all parts of the sky?

a)

It is produced by black holes in our galaxy

b)

It comes from Earth’s atmosphere

c)

It is a uniform glow from the early universe

d)

It is emitted by nearby stars only

70.

Which term describes the observed increase in wavelength when a light source moves away from an observer?

a)

Parallax

b)

Refraction

c)

Redshift

d)

Blue shift

71.

The nearly uniform glow of leftover radiation from the early universe is known as the __________________________.

a)

interstellar dust glow

b)

cosmic background radiation

c)

solar wind emission

d)

planetary nebula light

72.

In a red-shifted galaxy spectrum, the light waves are stretched toward the __________________ end of the spectrum.

a)

long-wavelength red

b)

ultraviolet violet

c)

short-wavelength blue

d)

midrange green

73.

Fusion reactions in stars produce energy by combining lighter elements into heavier ones, releasing _________________ in the process.

a)

electrical current

b)

chemical energy

c)

gravitational waves

d)

radiation and heat

74.

Once a high-mass star forms iron in its core, the fusion process stops producing energy and instead __________________ energy, leading to a collapse and supernova.

a)

absorbs rather than releases

b)

stores excess

c)

converts kinetic

d)

doubles available

75.

Which of the following elements is most likely to be formed during a supernova explosion?

a)

Helium

b)

Carbon

c)

Gold

d)

Hydrogen

76.

What is the final stage in the life cycle of a medium-mass star like the Sun?

a)

Supernova

b)

Red supergiant

c)

Black hole

d)

White dwarf

77.

Based on the plotted curve of relative abundance by atomic number, which trend is most apparent?

a)

Elements decline with bumps

b)

Elements stay constant

c)

Elements rise steadily

d)

Elements peak at iron

78.

Why does fusion up to iron release energy but fusion of iron does not?

a)

Iron has fewer protons

b)

Gravity stops working

c)

Binding energy per nucleon

d)

Electrons become unstable

79.

After a supernova of a high-mass star, which remnant can form?

a)

Neutron star remnant

b)

White dwarf remnant

c)

Brown dwarf remnant

d)

Cometary remnant

80.

What observation indicates the universe is expanding?

a)

Galactic red shifts

b)

Solar flares

c)

Planetary eclipses

d)

Lunar phases

81.

Which of the following best explains why we find uranium and lead on Earth?

a)

They formed inside Earth’s core due to heat and pressure

b)

They formed in the solar wind and were deposited on the planet

c)

They were synthesized in supernovae and recycled into new planetary systems

d)

They are condensed from hydrogen gas during the Sun’s formation

82.

A star's light is split into a spectrum showing dark lines at specific wavelengths. What do these lines tell scientists?

a)

The temperature of nearby galaxies

b)

The star’s brightness over time

c)

The elements present in the star’s outer layers

d)

The age of the star

83.

A star’s absorption lines appear shifted slightly toward the blue end of the spectrum. What can be concluded?

a)

The star is moving away from Earth

b)

The star is stationary

c)

The star is losing mass rapidly

d)

The star is approaching Earth

84.

Two stars have the same surface temperature, but one is significantly more luminous. What could explain this difference?

a)

The more luminous star is rotating faster

b)

The more luminous star is younger

c)

The more luminous star is larger in radius

d)

The more luminous star is smaller

85.

A star is classified as a white dwarf. Based on its position on the H–R Diagram, what are its likely characteristics?

a)

Hot and dim

b)

Cool and dim

c)

Hot and bright

d)

Cool and large

86.

On an H–R Diagram, main sequence stars show a trend where temperature and __________ increase together.

a)

lifetime

b)

rotation

c)

luminosity

d)

distance

87.

The giant and supergiant stars are found in the __________ region of the diagram due to their high luminosity and large size.

a)

upper right

b)

lower right

c)

center band

d)

lower left

88.

Which of the following best explains how nuclear fusion powers the Sun?

a)

Atoms of heavy elements are split apart, releasing heat

b)

Hydrogen atoms combine to form helium, releasing energy

c)

Protons are converted into neutrons without energy output

d)

Radiation from the Sun's surface generates internal fusion

89.

Why do astronomers use space-based telescopes to observe X-rays and gamma rays?

a)

High-energy radiation only originates from the Moon

b)

These wavelengths are easier to detect during the day

c)

Earth's rotation makes these observations difficult

d)

The atmosphere blocks most high-energy radiation

90.

Which tool is most often used to identify the elements present in a distant star?

a)

Electron microscope

b)

Spectroscope

c)

Seismometer

d)

Radio antenna

91.

In a fusion reaction, hydrogen nuclei combine to form ____________, releasing energy in the process.

a)

helium nuclei

b)

carbon atoms

c)

oxygen molecules

d)

neutron stars

92.

The electromagnetic radiation produced by fusion travels through space as ______________.

a)

gravity ripples

b)

sound waves

c)

ocean tides

d)

electromagnetic waves

93.

Which statement best explains why certain wavelengths must be observed from space rather than ground-based telescopes?

a)

The atmosphere absorbs many high-energy wavelengths

b)

Space telescopes have larger mirrors than ground ones

c)

Cloud cover increases the brightness of stars

d)

Mountains block long radio wavelengths

94.

Which pair lists types of electromagnetic waves useful for studying non-visible parts of the universe?

a)

Infrared and ultraviolet

b)

AM radio and sonar

c)

Microwaves and thunder

d)

Visible light and sound

95.

A student wants to determine the chemical composition of a star. Which method should they use?

a)

Record seismic activity with a seismometer

b)

Capture images with a radio antenna

c)

Measure star brightness with a photometer

d)

Analyze its spectrum with a spectroscope

96.

Which observation would most likely require a space-based telescope?

a)

Tracking cloud movement on Earth

b)

Counting sunspots with binoculars

c)

Detecting gamma rays from a supernova

d)

Mapping city light pollution

97.

Which sequence correctly describes energy production in stars like the Sun?

a)

Conduction moves heat through solid metal

b)

Combustion burns oxygen to release heat

c)

Fusion combines hydrogen nuclei into helium

d)

Fission splits heavy nuclei into smaller ones

98.

Which reason best supports placing telescopes in orbit around Earth?

a)

To reduce the need for electricity

b)

To avoid nighttime temperatures

c)

To eliminate atmospheric distortion and absorption

d)

To shorten the distance to nearby stars

99.

Which space-based technology is specifically designed to collect data about stars and galaxies by detecting light across many wavelengths?

a)

Ground-based radio antenna arrays

b)

Space telescopes with multiwavelength instruments

c)

Deep-sea neutrino observatories

d)

Weather satellites monitoring cloud patterns

100.

What process powers the Sun and is responsible for the energy that ultimately reaches Earth?

a)

Nuclear fission in the solar core

b)

Nuclear fusion of hydrogen into helium

c)

Chemical combustion of hydrogen gas

d)

Radioactive decay of heavy elements

101.

Which term best describes matter composed of charged particles found in stars and the solar wind?

a)

Magma

b)

Alloy

c)

Plasma

d)

Vapor

102.

Which part of the electromagnetic spectrum is most useful for observing cooler objects like interstellar dust?

a)

Microwaves used for cooking food

b)

Visible light from human-eye wavelengths

c)

Infrared radiation emitted by cool matter

d)

Gamma rays with extremely high energy

103.

A scientist uses spectroscopy to study a star. What information is most directly obtained from its spectrum?

a)

Daily weather on the star’s surface

b)

Precise age of the universe

c)

Chemical elements present in the star

d)

Exact mass of each planet

104.

Which statement explains how nuclear fusion contributes to stellar evolution?

a)

Fusion only occurs during star formation then ceases

b)

Fusion splits heavy nuclei into lighter fragments

c)

Fusion builds heavier nuclei from lighter ones over time

d)

Fusion stops energy production as stars age

105.

Why are space-based telescopes essential for observing ultraviolet light from distant galaxies?

a)

Ultraviolet light cannot travel through vacuum

b)

Earth’s atmosphere absorbs much ultraviolet light

c)

Earth’s oceans absorb ultraviolet wavelengths completely

d)

Earth’s core blocks ultraviolet radiation

106.

Which pair represents two different types of evidence that can support a claim about galaxy formation?

a)

Volcano ash samples and earthquake records

b)

Ultraviolet spectra and infrared images

c)

Surface ocean currents and wind speed data

d)

Soil pH readings and plant growth charts

107.

If a claim states that fusion research benefits life on Earth, which example best supports it?

a)

Fusion makes metal alloys stronger for bridges

b)

Fusion improves cloud seeding for rainfall

c)

Fusion accelerates plant photosynthesis rates

d)

Fusion enables cleaner, high-density energy sources

108.

Which key term should be used to describe a technique that separates light into its component wavelengths to analyze composition?

a)

Spectroscopy

b)

Refraction

c)

Photoelectricity

d)

Diffusion

109.

Which observation supports that the universe is expanding outward in all directions?

a)

Planets orbit in perfect circles

b)

Stars appear blue in most spectra

c)

Galaxies show redshifted light consistently

d)

Comets return on predictable schedules

110.

What does redshifted light from distant galaxies indicate about their motion?

a)

They are stationary in space

b)

They are moving toward us

c)

They are rotating faster

d)

They are moving away from us

111.

Which evidence demonstrates uniformity and remnants of early high-energy radiation in the universe?

a)

Solar wind particle streams

b)

Auroras near polar regions

c)

Cosmic Microwave Background Radiation

d)

Infrared emission from dust

112.

A galaxy’s emitted light shifts toward the red end of the spectrum. What does this provide evidence for?

a)

Increase in cosmic dust

b)

Formation of planetary rings

c)

Cooling of star surfaces

d)

Expansion of the universe

113.

In stellar fusion, combining hydrogen into helium primarily releases what?

a)

Large amounts of energy

b)

Heavy metal elements

c)

Intense magnetic fields

d)

Stable planetary systems

114.

When a massive star’s core can no longer gain energy from iron fusion, what happens next?

a)

The core expands and cools steadily

b)

Fusion accelerates, stabilizing the core

c)

Energy input is required, leading to core collapse

d)

Radiation pressure overcomes gravity

115.

Elements heavier than iron, such as gold, are mainly formed during which event?

a)

Supernova explosions

b)

Planetary nebulae ejection

c)

Main-sequence burning

d)

Black hole accretion

116.

After the outer layers are shed, which compact stellar remnant can remain from a medium-mass star?

a)

Brown dwarf

b)

Neutron star

c)

Red giant

d)

White dwarf

117.

Hubble’s Law describes a relationship between which two properties of galaxies?

a)

Brightness and chemical composition

b)

Mass and internal temperature

c)

Age and rotational speed

d)

Distance and recessional velocity

118.

Why does light from receding galaxies stretch to longer wavelengths?

a)

Gravitational lensing by clusters

b)

Doppler effect due to motion away

c)

Refraction through interstellar gas

d)

Absorption by cosmic dust lanes

119.

Which feature in a star’s spectrum helps identify elements present in its outer layers?

a)

Continuous color bands across all wavelengths

b)

Unique absorption lines at specific wavelengths

c)

Random bright spots scattered across the spectrum

d)

Uniform dark background with no variation

120.

A shift toward the blue end of a star’s spectrum indicates what about the star’s motion?

a)

It is moving toward the observer

b)

It is moving away from the observer

c)

It has increased surface temperature

d)

It is rotating faster around its axis

121.

What does the Doppler effect describe in astronomy?

a)

How temperature determines a star’s color

b)

How stars generate energy in their cores

c)

How motion changes the observed wavelength of light

d)

How gravity bends the path of starlight

122.

Why are spectral lines useful for astronomers studying stars?

a)

They reveal the star’s total mass directly

b)

They provide unique fingerprints for element identification

c)

They measure the star’s age with high precision

d)

They show the star’s exact distance without error

123.

Astronomers observe helium and iron absorption lines in a star’s spectrum. What conclusion can they draw?

a)

The star is rotating unusually slowly

b)

The star is cooling rapidly

c)

Helium and iron exist in the star’s atmosphere

d)

The star is a white dwarf

124.

If spectral lines are redshifted, what does this indicate about the star’s motion relative to Earth?

a)

It is rotating, wavelengths alternating

b)

It is moving away from Earth, wavelengths stretched

c)

It is stationary, wavelengths unchanged

d)

It is moving toward Earth, wavelengths compressed

125.

For main sequence stars, how does luminosity change as temperature increases from left to right on the H–R Diagram?

a)

Luminosity decreases steadily top to bottom

b)

Luminosity remains constant across all types

c)

Luminosity fluctuates without a clear trend

d)

Luminosity increases from bottom to top

126.

Where are white dwarfs located on the H–R Diagram and what are their typical properties?

a)

Upper right; cool and very bright

b)

Lower left; hot and very dim

c)

Upper left; hot and very bright

d)

Center region; moderate and stable

127.

If two stars have the same temperature, which star is more luminous?

a)

The star with faster rotation

b)

The star with smaller radius

c)

The star with larger radius

d)

The star with stronger magnetic field

128.

Elements heavier than iron are most likely formed through which type of events?

a)

Slow cooling of planetary atmospheres

b)

Steady hydrogen fusion in stellar cores

c)

Collisions between asteroids in space

d)

Rare high-energy events like supernovae

129.

Which process powers stars by combining hydrogen atoms into helium, releasing energy?

a)

Gravitational compression only

b)

Hydrogen fusion into helium

c)

Nuclear fission in star cores

d)

Chemical combustion of gases

130.

Which part of Earth most strongly blocks X-rays and gamma rays from reaching ground-based telescopes?

a)

The oceanic crust layer

b)

Earth’s atmosphere layer

c)

Mountain ranges barrier

d)

The outer core layer

131.

What instrument separates incoming light into spectra to identify elements in stars?

a)

Spectroscope for light spectra

b)

Seismograph for ground waves

c)

Microscope for tiny objects

d)

Barometer for air pressure

132.

In stellar fusion, which element is primarily produced from hydrogen at typical core conditions?

a)

Carbon from triple reactions

b)

Helium from proton fusion

c)

Iron from end-stage burning

d)

Oxygen from partial fusion

133.

Energy from stellar fusion reaches Earth mainly as which type of radiation?

a)

Electromagnetic waves spectrum

b)

Mechanical sound vibrations

c)

Seismic crustal waves

d)

Neutron particle fluxes

134.

Which wavelength can reveal heat from dust clouds that block visible light, helping locate star-forming regions?

a)

Radio waves from galaxies

b)

Infrared waves from dust

c)

Ultraviolet waves from stars

d)

Microwaves from cosmic background

135.

Observations of high-energy areas around black holes and exploding stars are best made using which wavelengths?

a)

X-rays from energetic zones

b)

Infrared light from dust

c)

Radio waves from pulsars

d)

Visible light from photospheres

136.

Why do scientists place telescopes in space rather than only on the ground?

a)

To avoid clouds only

b)

To escape atmospheric blocking

c)

To reduce instrument cost

d)

To stay closer to stars

137.

Which statement best explains a benefit of the James Webb or Chandra X-ray Observatory?

a)

They forecast local weather

b)

They map tectonic plate motion

c)

They collect clearer space data sets

d)

They measure ocean currents precisely

138.

On an H–R Diagram, where are giants and supergiants typically located due to low temperatures and high luminosities?

a)

Upper right region area

b)

Center main sequence band

c)

Lower left region area

d)

Upper left region area

139.

Which telescope is highlighted for using infrared wavelengths to study early galaxies?

a)

Chandra X-ray Observatory for hot gas

b)

James Webb Space Telescope using infrared

c)

Spitzer Telescope for radio emissions

d)

Hubble Space Telescope for visible light

140.

Why is a space-based infrared telescope necessary for observing early galaxies?

a)

Infrared cannot pass through lenses

b)

Atmosphere absorbs much infrared light

c)

Earth's rotation blurs all observations

d)

Galaxies only emit radio signals

141.

What stellar process powers stars and produces energy that reaches Earth?

a)

Nuclear fusion of hydrogen

b)

Gravitational collapse of dust

c)

Chemical burning of helium

d)

Magnetic reconnection in cores

142.

During nuclear fusion in stars, hydrogen atoms fuse into which element?

a)

Helium created by fusion

b)

Oxygen produced by burning

c)

Carbon formed in cores

d)

Nitrogen from cosmic rays

143.

Which statement best describes how spectroscopy helps scientists?

a)

It analyzes light to reveal composition

b)

It measures star masses directly

c)

It maps gravity fields precisely

d)

It photographs planets in color

144.

What role does electromagnetic radiation play in the energy from stars?

a)

It stores energy inside cores

b)

It cools stars by conduction

c)

It carries energy from fusion

d)

It blocks energy in atmospheres

145.

Which reason explains why the James Webb Space Telescope studies through dust clouds?

a)

Infrared passes through dust better

b)

Visible light reflects off dust

c)

Radio waves scatter heavily

d)

X-rays absorb in dust strongly

146.

Which consequence of nuclear fusion helps sustain life on Earth?

a)

It slows Earth's orbital speed

b)

It increases atmospheric oxygen

c)

It emits energy that warms Earth

d)

It reduces Earth's magnetic field

147.

Combining spectroscopy with fusion knowledge allows scientists to do what more effectively?

a)

Control solar flares on the Sun

b)

Measure Earth's interior heat flow

c)

Explain star structure and processes

d)

Predict asteroid impacts precisely

148.

Which statement best summarizes the value of space-based technologies and discoveries?

a)

They replace all ground telescopes

b)

They provide deeper insight into origins

c)

They eliminate atmospheric weather

d)

They make stars brighter for viewing