GED Science Earth and Space Science 5 — Questions and Answers
Question 1: Which atmospheric gas has increased most significantly due to human industrial activity and is the primary driver of current climate change?
- Oxygen (O₂)
- Nitrogen (N₂)
- Carbon dioxide (CO₂) (Correct answer)
- Argon (Ar)
Correct answer: Carbon dioxide (CO₂)
Burning fossil fuels and deforestation have substantially raised atmospheric CO₂ concentrations, enhancing the greenhouse effect and driving global temperature increases.
Question 2: What term describes the bending of light as it passes from one medium to another, such as from air into water?
- Reflection
- Diffraction
- Refraction (Correct answer)
- Absorption
Correct answer: Refraction
Refraction occurs because light changes speed when it enters a new medium, causing it to bend at the interface — this is why a straw appears broken in a glass of water.
Question 3: The outer layer of Earth, consisting of the crust and uppermost mantle, is broken into moving pieces called:
- Tectonic plates (Correct answer)
- Magma chambers
- Asthenosphere segments
- Isostatic blocks
Correct answer: Tectonic plates
Tectonic plates are rigid sections of Earth's lithosphere that move slowly over the semi-fluid asthenosphere, driving earthquakes, volcanoes, and mountain formation.
Question 4: Which characteristic is used to measure the brightness of a star as seen from Earth?
- Absolute magnitude
- Apparent magnitude (Correct answer)
- Luminosity class
- Spectral type
Correct answer: Apparent magnitude
Apparent magnitude measures how bright a star appears from Earth, and it depends on both the star's actual brightness and its distance from us.
Question 5: What is the source of energy that drives Earth's weather and ocean circulation systems?
- Earth's internal heat from radioactive decay
- The Moon's gravitational pull
- Energy radiated from the Sun (Correct answer)
- Geothermal vents on the ocean floor
Correct answer: Energy radiated from the Sun
Solar radiation is the primary energy source driving atmospheric circulation, ocean currents, the water cycle, and most weather patterns on Earth.
Question 6: Which type of rock is formed when existing rocks are changed by extreme heat and pressure without melting?
- Sedimentary
- Igneous
- Metamorphic (Correct answer)
- Volcanic
Correct answer: Metamorphic
Metamorphic rocks form when existing rocks are subjected to high heat and pressure deep within Earth, altering their mineral structure without completely melting them.
Question 7: The 'Big Bang' theory proposes that the universe began approximately how many years ago?
- 4.6 billion years ago
- 13.8 billion years ago (Correct answer)
- 6,000 years ago
- 100 billion years ago
Correct answer: 13.8 billion years ago
Current cosmological evidence, including cosmic microwave background radiation and the observed expansion of the universe, indicates the Big Bang occurred about 13.8 billion years ago.
GED Science Earth and Space Science 5
Which atmospheric gas has increased most significantly due to human industrial activity and is the primary driver of current climate change?