What is the unique property of mercury compared to other metals?

Mercury is unique among metals because it exists in a liquid state at room temperature. This characteristic sets it apart from most other metals, which are typically solid under similar conditions. The liquid state of mercury is due to its atomic structure and the weak metallic bonds that form between its atoms, which do not allow them to pack closely together as they do in solid metals. This property enables mercury to flow and take the shape of its container, making it useful in various applications such as thermometers and barometers. The other options inaccurately describe the physical state of mercury; it is not a gas or a nonmetal, and it certainly does not solidify until temperatures are significantly lowered.