GED Science Test #4 3 — Questions and Answers
Question 1: The pH of a substance is 3. This substance is:
- Acidic (Correct answer)
- Basic
- Neutral
- Alkaline
Correct answer: Acidic
The pH scale ranges from 0–14. Values below 7 are acidic, 7 is neutral, and above 7 is basic (alkaline). A pH of 3 indicates a strongly acidic substance.
Question 2: Which layer of Earth's atmosphere contains the ozone layer?
- Stratosphere (Correct answer)
- Troposphere
- Mesosphere
- Thermosphere
Correct answer: Stratosphere
The ozone layer is found in the stratosphere, 15–35 km above Earth's surface. It absorbs most of the sun's ultraviolet radiation, protecting life on Earth.
Question 3: A food web shows: grass → grasshopper → frog → snake → hawk. If the frog population suddenly declines, what would most likely happen to the grasshopper population?
- Increase (Correct answer)
- Decrease
- Stay the same
- Go extinct immediately
Correct answer: Increase
If frogs (predators of grasshoppers) decline, there is less predation pressure on grasshoppers, so their population would likely increase. This is a cascading effect in food webs.
Question 4: Which of Newton's laws states that an object at rest stays at rest unless acted upon by a net external force?
- First Law (Law of Inertia) (Correct answer)
- Second Law (F = ma)
- Third Law (Action-Reaction)
- Law of Universal Gravitation
Correct answer: First Law (Law of Inertia)
Newton's First Law describes inertia — the tendency of objects to resist changes in their state of motion. An object at rest remains at rest, and an object in motion stays in motion, unless an unbalanced force acts on it.
Question 5: During photosynthesis, plants convert:
- Carbon dioxide and water into glucose and oxygen (Correct answer)
- Oxygen and glucose into carbon dioxide and water
- Sunlight directly into food energy
- Nitrogen and water into protein
Correct answer: Carbon dioxide and water into glucose and oxygen
Photosynthesis uses sunlight, CO₂, and water to produce glucose (food) and oxygen. The equation is: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂.
Question 6: A bar graph shows the following data: City A = 18°C average temperature; City B = 24°C. City B is located closer to the equator. Which inference is best supported?
- Proximity to the equator is associated with higher average temperatures (Correct answer)
- City A has a colder climate due to elevation
- Temperature differences are caused by ocean currents
- Both cities receive the same amount of sunlight
Correct answer: Proximity to the equator is associated with higher average temperatures
The data shows City B (closer to equator) has a higher average temperature. The most direct inference is that latitude/proximity to the equator is associated with higher temperatures.
GED Science Test #4 3
The pH of a substance is 3.
This substance is: