GED Science Test #4 3

Question 1

The pH of a substance is 3. This substance is:

Accepted Answer

Acidic

Answer

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?

Accepted Answer

Stratosphere

Answer

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?

Accepted Answer

Increase

Answer

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?

Accepted Answer

First Law (Law of Inertia)

Answer

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:

Accepted Answer

Carbon dioxide and water into glucose and oxygen

Answer

Photosynthesis uses sunlight, CO₂, and water to produce glucose (food) and oxygen. The equation is: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂.

GED Practice Test

GED Practice Test

GED Science Test #4 3