Question

what happens first when a star begins to run out of fuel?
○ the star’s core shrinks.
○ the star becomes a black hole.
○ the star becomes a white dwarf.
○ the star’s outer layer drifts away.

Explanation:

To solve this, we analyze each option:

• Option 1: When a star runs out of fuel (like hydrogen for fusion), the outward pressure from fusion stops. Gravity then causes the star’s core to shrink first as it tries to find a new equilibrium.
• Option 2: A star becomes a black hole only in specific, later stages for very massive stars, not the first event.
• Option 3: Becoming a white dwarf is a later stage (after core shrinkage and other processes), not the first thing.
• Option 4: The outer layer drifting away (like in planetary nebula formation) happens after the core has already shrunk and other internal changes occur.

So the first event is the star’s core shrinking.

Answer:

The star’s core shrinks.