When Ag+ is combined with Na2CO3, the substances formed are Ag2CO3 and Na+. In this case, Ag performs single substitution over the element Na to form another set of substances. There are other types of reactions like double displacement, decomposition, etc.
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air. These solid particles become pyroclasts or volcanic ash.
metallic bonds occur among the metal atoms where iconic bonds join metal and nonmetals metallic bonding joins a bolt of metal atoms a sheet of aluminum foil and a copper wire are both place where you can see metallic bonding in action the Sea of electrons that is free to flow about the crystal of positive metal ions