When you dissolve covalent compounds in water, the molecules tend to stick together but if you dissolve ionic compounds in water, the formula units tend to disassociate. What can you infer about which type of bond is stronger?

How is it possible for someone to put an ear to a wall and hear someone in the next room?     a.sound waves can travel though solids.    b.the waves travel from room to room via air.    c.there must be some air in the wall so the sound can travel through it.    d.sound waves change to electromagnetic waves and then back again.