Question

oxygen gas is used to fill a balloon and a short time later the balloon is observed to only be half full. explain this observation.
○ the balloon leaks and the temperature went down.
○ more oxygen was added to the balloon and the temperature went up.
○ the pressure outside the balloon went down and the pressure inside went down.
○ the pressure outside the balloon went down and the temperature inside went up.

Explanation:

A balloon filled with oxygen deflating to half full is due to gas escaping (leaking) over time. Balloons are not perfectly impermeable, so small oxygen molecules can gradually pass through the balloon material. A temperature drop would cause contraction but would not typically reduce the volume by half without an extreme temperature change, and changes in external pressure or adding more oxygen would not result in a deflated balloon.

Answer:

A. The balloon leaks and the temperature went down.