Magnetic Resonance Safety Expert (MRSE) Practice Exam

When liquid helium expands into gas, it undergoes a significant increase in volume. The transition from liquid to gas happens at low temperatures and results in helium gas occupying a much larger space compared to its liquid form.

For helium, specifically, 1 liter of liquid helium can expand to approximately 750 liters of gas at room temperature and atmospheric pressure. This significant expansion can be attributed to the properties of helium, including its low boiling point and its molecular structure that allows it to occupy a much greater volume as a gas compared to its liquid state.

This fundamental characteristic of helium makes it essential for various applications in cryogenics and MR technology, where it serves as a coolant due to its efficiency in both liquid and gaseous forms. Understanding this expansion ratio is crucial for safety considerations and operational protocols within magnetic resonance environments where helium is used.

Thus, the choice indicating that 1 liter of liquid helium expands to about 750 liters of gas is indeed accurate, reflecting the behavior of helium in these phases.