Explain how you could find out whether or not an unknown liquid is water.

We can use the physical properties of water such as density, melting point and boiling point, etc to determine if a liquid is water. Water has a density of 1 gm/cm^3 or 1000 kg/m^3. We can measure the mass of one cm^3 or 1 m^3 of the unknown liquid and check against the mass of equivalent volume of water.

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