Discussion Questions
1. The Earth’s magnetic field is generated by
1.
electric currents in the liquid outer core; it has never changed
direction.
2.
electric currents in the liquid inner core; it has never changed
direction.
3.
electric currents in the liquid outer core; it has reversed many
times in the past.
4.
electric currents in the liquid inner core; it has reversed many times
in the past.
2. Which of the following best describes the natural
greenhouse effect on Earth?
1.
Scientists are unsure if there is a greenhouse effect.
2.
There is a weak greenhouse effect that keeps the average
temperature above freezing.
3.
There is a weak greenhouse effect that raises the average temperature
by a fraction of a degree.
4.
There is a weak greenhouse effect that keeps the surface of the Earth
cooler than it otherwise would be.
Discussion Questions
3. In the greenhouse effect,
a.
some infrared radiation emitted by the Earth’s surface is
absorbed by the atmosphere.
b.
some ultraviolet radiation emitted by the Earth’s surface is absorbed
by the atmosphere.
c.
infrared radiation from the Sun is captured as it enters the Earth’s
atmosphere.
d.
infrared radiation from the Sun is reflected by the Earth’s
atmosphere into space.
4. Which of the following is the most likely way the Moon
formed?
a.
Asteroid debris from space was collected in Earth’s orbit, and this
material slowly coalesced to form the Moon
b.
A large body impacted the Earth during its early formation. This
material was ejected into space and eventually formed the Moon.
c.
The Moon formed elsewhere in the solar system and was later captured
by the Earth.
d.
The Moon is merely a large captured asteroid.