Both covalent-network solids and ionic solids can have melting points well in excess of room temperature, and both can be poor conductors of electricity in their pure form. however, in other ways their properties are quite different.1.which type of solid is more likely to dissolve in water? 2.which type of solid can become a considerably better conductor of electricity via chemical substitution?

1. Ionic solids dissolve in water.

2. Ionic solid is a better conductor compared to covalent solid.

Explanation:

1. Ionic solids dissolves in water because the water molecules hydrate the ions.When ionic compounds dissolve in water, they break apart into the ions that make them up through a process called dissociation.

Whereas covalent  solids don't dissolve in water, instead making a separate layer on the water's surface.

For example table salt that is NaCl is an ionic solid.When we add the salt in water it completely dissolves in water and disappears on the other hand oil is a covalent solid, when we add it in water it does not dissolve and forms a layer on water surface.

2.Ionic solids conducts electricity when it dissolves in water. Because in aqueous form there are ions which conducts electricity.

But covalent solids does not conduct in any form neither in pure form nor in aqueous form because they are bond with shared electrons having no ions which conducts electricity.

the answer is 75.0%.