Which of the following is true about ionic compounds?

Ionic compounds are formed through the transfer of electrons from one atom to another, typically between metals and non-metals, resulting in the formation of positive and negative ions. Their structural characteristics, including high melting points due to strong electrostatic forces between ions, differentiate them from covalent compounds, which involve sharing of electrons.

The statement that ionic compounds conduct electricity when dissolved in water is accurate. When ionic compounds dissolve in water, they break apart into their constituent ions. These free-moving ions can carry an electric current, which is why solutions of ionic compounds can conduct electricity. This property is essential in many chemical processes and applications, such as in electrolysis.

In contrast, the other choices do not apply to ionic compounds. They do not form through electron sharing, and their melting points are generally high, not low. Furthermore, ionic compounds are not typically volatile; instead, they usually form solid crystals at room temperature, which is indicative of stable ionic lattices rather than gaseous states.