 So you can predict whether a metal will displace the ions of a less active metal by looking at an activity series. So over here we have an activity series that we could look at. So the more active metal oxidizes to its ion, the less active metal's ions are reduced to the solid metal. So let's have a look. What would occur when an ion now is submerged in a zinc nitrate solution? So let's have a look. We'll look through our activity series. We have ion here, and we have zinc here. So in this case we're putting an ion now which is less active into a solution of a more active metal. So in this case what's going to happen? Nothing. So the zinc placed in an ion solution, we would see a reaction, but the solid ion being placed in a zinc solution, we have a less active metal being placed in a solution of a more active metal's ions. These ions are already oxidized, they're already really stable. So they're not going to go back spontaneously unless we put in energy for example. So in this case nothing would happen. So in this question we've got solid chromium going into the solution of sodium ion. So let's find where they are. So here's chromium, and here's sodium. So I think again we have a solid metal that is less active than the ions of the metal in the solution that it's going into. So again what's going to happen here, nothing. And again to explain, sodium oxidizes really easily. So it's oxidizing to its ions very very easily. And that means it's very hard to push it back the other way. So the chromium oxidizing here is not going to be able to force by producing electrons. It's not going to be able to force the sodium ions to reduce back to the solid sodium. You need to put in an awful lot of energy to get that to happen. So in this case the reaction won't happen again either. Let's look at this example. So now we've got nickel and lead. So let's find nickel. So here's nickel, and here's lead. So now our solid, nickel, is more active than the solution that's being put. So the lead ions are aqueous down here. So in this case the reaction will happen. So let's figure out what's happening. So the nickel is more active so it's going to be oxidized. So the solid nickel is going to be oxidized. So nickel is going to go to nickel ions. So we're going nickel 2 plus plus 2 electrons. The lead ions in the solution are going to be reduced. So the PB2 plus, the lead 2 plus ions plus 2 electrons goes to solid lead. So here we have oxidation. Oxidation is lost. Here we have reduction. Reduction is gained. So lead ions are gaining electrons to form solid lead. So our overall equation is nice and easy here because the electrons all cancel out. So we've got nickel, solid plus lead ions, PB2 plus, ions in solution, aqueous, goes to nickel ions, aqueous. And we would see solid lead forming around the piece of nickel. So lead, solid. Right, our last example is reacting magnesium with silver ions. So down here we have a video playing and thanks to resource for doing this. So there's a mixture of solid magnesium powder and a silver salt. And some water has been sprayed on this. So you can see the water drops coming in. And then we get a big explosion happening. So what's happening there? Well, let's find out our metals here. So we've got magnesium up here and we've got silver down here. So there's a big gap in reactivity. And when that happens, that means you get usually fairly big reactions happening because there's a big difference in energy between the oxidation and the reduction reactions. So that partially explains the big explosion here. The other reason for the explosion is magnesium when it catches on fire gives off a nice big white flame. So the energy being produced is enough to catch the magnesium powder on fire so we get a nice big explosion. So we have a more active metal, in this case magnesium, in a solution when we fluid the water on of a less active metals ion. So that's silver down here. So we will get a reaction as we just saw in the video. So the magnesium is being oxidized. So magnesium goes to magnesium ions, two plus plus two electrons. So the magnesium is really reactive so it gives off its electrons really readily. The silver ions from the salt in the mix down here, they are going to be reduced. Silver ions readily reduce, it's really low on the reactivity series. So the silver ions again plus an electron are going to solid silver. So now we can do our reaction equation. And again, we're going to have to multiply the bottom one here by two to balance out the number of electrons. And I'm just going to assume that's happened. So the magnesium is reacting with two silver ions and that produces magnesium ions and two silvers. So solid silver would be being produced here, but that would explode with the magnesium that's left over. Magnesium ions in that little bit of water there. Silver ions and solid magnesium over here. So today on Flipping Science we looked at metal activity and how that applies to displacement reactions. That's it for Flipping Science today. See ya.