The following text discusses a scientific phenomenon.
The Northern Lights, or aurora borealis, occur when charged particles from the sun interact with Earth's magnetic field. These particles are channeled toward the poles, where they collide with atmospheric gases and produce spectacular light displays. The colors vary depending on which gas molecules are struck: oxygen produces green and red, while nitrogen creates purple and blue. Though most common in Arctic regions, particularly strong solar events can make the aurora visible at lower latitudes.
According to the text, what determines the colors of the Northern Lights?
The temperature of the atmosphere
The type of gas molecules struck by solar particles
The time of year the aurora occurs
The distance from the North Pole
Correct Answer: B
Choice B is the correct answer. The text explicitly states "colors vary depending on which gas molecules are struck"—oxygen for green/red, nitrogen for purple/blue.
- Evidence: Specific colors linked to specific gases.
- Reasoning: The collision with different gases creates different colors.
- Conclusion: Gas type determines color.
Choice A is incorrect because temperature is not mentioned as a factor. Choice C is incorrect because season is not discussed. Choice D is incorrect because distance doesn't determine color, though it affects visibility.