Unit 9: Astronomy Review

Which statement describes the motion of Earth around the sun?

• The speed of Earth is constant regardless of its distance from the sun.

• The speed of Earth is constant because the distance remains the same between Earth and the sun.

• Speed increases the farther Earth is from the sun and decreases the closer it is to the sun.

• Speed increases the closer Earth is to the sun and decreases the farther it is from the sun.

If it is summer in the northern hemisphere, which statement is true?

• Earth has changed the tilt of its axis by 20 degrees due to its revolution.

• It is winter in the southern hemisphere due to the tilt of Earth’s axis.

• It is summer in the southern hemisphere due to the tilt of Earth’s axis.

• Earth has reached its closest point to the sun due to its revolution

How does a straight alignment between Earth, the sun, and the moon impact the tides on Earth?

• It produces the greatest change in high and low tides.

• It produces the least change in high and low tides.

• It produces semidiurnal tides.

• It produces diurnal tides.

Which describes the difference between nuclear fission and nuclear fusion?

• Nuclear fission is the process that produces the radiant energy of stars, and

  nuclear fusion splits a heavier nucleus into smaller nuclei

• Nuclear fission splits a heavier nucleus into smaller nuclei, and nuclear

  fusion is the process that produces the radiant energy of stars.

• Nuclear fission produces the energy in the core of Earth, and nuclear fusion

  produces energy in nuclear power plants.

• Nuclear fission produces energy in nuclear power plants, and nuclear fusion

  produces the energy in the core of Earth.

How does heat from the sun get to Earth?

• by radiation, using electromagnetic waves to transfer the heat

• by convection, using liquids and gases to transfer the heat

• by conduction, using solids to transfer the heat

• by absorption, using primary waves to transfer the heat

Why do green plants require solar energy?

• to produce their own food

• to absorb nitrogen into their roots

• to release carbon dioxide into the atmosphere

• to decompose the dead or decaying remains of animals

Which natural phenomenon occurs as a result of Earth rotating on its axis?

• movement of tectonic plates

• deep ocean currents

• seasonal changes

• day and night

How does the tilt of the Earth’s axis affect the seasons?

• by changing the amount of direct solar energy reaching the surface of Earth

• by influencing the rate of chemical reactions occurring in the atmosphere

• by deflecting the harmful rays of radiation emitted by the sun

• by changing the speed of the rotation of Earth

Earth travels on an elliptical orbit around the Sun.

When Earth is at the point labeled on the diagram, it moves most quickly in its orbit. Which best explains this more rapid motion of Earth?

• The amount of solar heat reaching Earth is greatest at this point.

• The Sun’s gravitational pull on Earth is strongest at this point.

• Earth is closest to the Sun’s magnetic field at this point.

• Earth is closest to the Sun’s radioactivity at this point.

Nuclear fusion is the source of energy for stars. Besides hydrogen, which other element is most likely also common in stars?

• Helium

• Argon

• Nitrogen

• Carbon