Make a Gallium Beating Heart

Greetings fellow nerds. In this video we’re going to perform the famous gallium beating heart experiment. I have here a standard laboratory heater plate and i’m placing on it a vial containing 10mL of a 6M solution of sulfuric acid. The exact concentration isn’t critical so you can vary it somewhat. Now we put in about two grams of pure solid gallium metal and heat the solution to about 50 degrees Celsius. Don’t use too much gallium or it’ll be too heavy and flatten out completely on its own, ruining the experiment. Now as it heats, the gallium will melt and liquefy. The sulfuric reacts with the gallium to form a very thin layer of gallium sulfate. This sticks to the surface and increases the surface tension of the gallium, causing it to pull itself together into a sphere. The bubbles you’re seeing are actually bubbles of hydrogen as the gallium reacts. Anyway, if you want some gallium yourself, I got mine from a company called galliumsource.com which I've linked in the video description. If you use the coupon code “NurdRage” then they’ll also give you a 5% discount on everything they sell so be sure to use that. They will also sell to individuals. Ok the gallium is ready. Now gently touch the top of it with an iron nail or iron wire. The gallium will relax and flatten out. If you remove the iron the gallium will contract again. If the iron is held just high enough it will stop touching when the gallium relaxes. The gallium will then contract again and touch the iron, repeating the cycle and pulsing like a beating heart Although this one kind of looks like a heart attack. Anyway, what’s happening is the iron is slowly dissolving in the acid and releasing electrons. Normally these electrons go on to produce hydrogen but if the iron touches the gallium then the electrons conduct through the two metals and reduces the gallium sulfate back into gallium. Without the gallium sulfate the surface tension drops and the gallium relaxes, spreading out. If the iron is held in the right position, the gallium drops away and no longer receives electrons. The acid begins attacking the gallium again producing gallium sulfate and increasing surface tension. The gallium pulls itself back together into a sphere where it touches the iron again and the cycle repeats. This will not last forever though, eventually the gallium or the iron will dissolve too much or the solution will become too contaminated with metal salts to sustain the reaction. Anyway, that’s the gallium beating heart experiment. Thanks for watching, please subscribe, rate, and comment!