Is sio2 most likely a molecular, metallic, ionic, or covalent-network solid? silicon readily reacts to form silicon dioxide, , which is quite hard and is insoluble in water. is most likely a molecular, metallic, ionic, or covalent-network solid? sio2 is a molecular solid. sio2 is a metallic solid. sio2 is an ionic solid. sio2 is a covalent-network solid?