Water at room temperature is a

Water exists in liquid state at room temperature (typically 20-25°C or 68-77°F). This is because water's freezing point is 0°C and boiling point is 100°C at standard pressure. At room temperature, water is between these two phase transition points, so it remains liquid. The other options are incorrect because solids have fixed shapes, gases have no fixed volume, and plasma is an ionized high-energy state not found at room temperature.