Question

1. choose the best answer. why do massive stars have a shorter lifespan? they have higher concentrations of hydrogen. they burn their fuel much more quickly than smaller stars. they are influenced by nearby black holes. they have more flammable gas than plasma or liquid fuel.

Explanation:

To determine why massive stars have a shorter lifespan, we analyze each option:

• Option 1: Higher hydrogen concentration doesn't directly relate to shorter lifespan (massive stars do fuse hydrogen, but the rate is key).
• Option 2: Massive stars have stronger gravitational forces, leading to higher pressure and temperature in their cores. This causes them to fuse fuel (hydrogen, then heavier elements) much faster than smaller stars. Faster fuel consumption means they exhaust their fuel quicker, resulting in a shorter lifespan.
• Option 3: Influence by black holes is not a primary factor in a star's inherent lifespan.
• Option 4: Stars primarily use nuclear fusion of hydrogen (not "flammable gas" or liquid fuel) for energy.

So the correct reason is that massive stars burn their fuel much more quickly than smaller stars.

Answer:

They burn their fuel much more quickly than smaller stars.