If you smack two heavy metal balls together, the energy of their collision will be focused at such a small point that enough heat can be produced to literally burn a hole through paper. Try this at home: it smells like smoke, but let’s make it even hotter. First, I’ll need to rust up one of these balls - a bowl of water should do the trick. Ten days later, that’s a rusty meatball. We’ll wrap the other ball in aluminum foil, turn down the lights, put on some ear and eye protection, and start whacking until this happens. Did you see that? That is molten slag at more than 4,500 degrees Fahrenheit. Now, that didn’t happen because I’m so strong (even though I am), it happened because the colliding balls produced the ignition temperature needed for a thermite reaction. The aluminum reduced the iron oxide (the rust on the ball) to form aluminum oxide, elemental iron, and much more heat than I put in. Now, that’s what I call an exothermic redox!