Final answer:
For a covalent compound to be a liquid at room temperature, it must have a boiling point above room temperature (20°C). Water is a common example of such a covalent compound. The state of covalent compounds depends on their molecular interactions and the strength of intermolecular forces.
Step-by-step explanation:
The physical state of covalent compounds at room temperature can vary from being gases, liquids, or solids, depending on their boiling and melting points. To answer the question: For a compound to be a liquid at room temperature, its boiling point must be higher than the room temperature, which is typically around 20°C. Water, with a boiling point of 100°C, is an example of a covalent compound that remains a liquid at room temperature along with other compounds possessing similar or higher boiling points.
The physical properties, such as state, are influenced by the molecular interactions within the compound. These properties are subject to the strength of the intermolecular forces, which include hydrogen binding, London dispersion forces, and dipole-dipole interactions. Intermolecular forces are generally weaker in covalent compounds compared to the ionic bonds found in salts, which is why covalent compounds can have lower boiling and melting points.