Gallium is an amazing element. It is a metal but it is liquid below 85.58 deg F (29.76 deg C) which means it has some very unique properties. Gallium (buy it here) has some other credits to it's name besides just being an amazing liquid metal. In 1871, a Russian scientist named Dmitri Mendeleev developed the first widely accepted version of the Periodic Table. In his table, he left gaps and explained that elements would exist in these gaps but that scientists had not yet discovered them. Most scientists of the time thought he was crazy! Five years later Gallium was discovered and it perfectly fit into one of the gaps in Mendeleev's Periodic Table just as he had predicted!
Once Gallium was able to be extracted from ores in a greater abundance, scientists began to experiment with it and a new parlor trick was developed. Chemists would form the liquid gallium into a spoon and would give the spoon to their guests at tea time (or so the story goes). When the guest would stir the hot tea with the gallium spoon, it would melt and disappear into the bottom of the cup. How valid is this story? It is really anyone's guess but it does highlight the unique properties of gallium and the unique sense of humor of chemists!
How to make a Gallium Spoon
I tried to make gallium spoon mold at least 4 different ways and had absolutely no success with any of my methods. I guess this just goes to show you how many failures I actually go through with many of my experiments! Eventually I determined it would be worth my time to look for a mold that would work for this experiment. After some searching, I found a special mold made especially for molding gallium spoons! The mold (find it here) is made by RotoMetals and works like a charm!
Gallium Spoon Mold (you may make your own or order one by clicking here)
Hot water (water boiler)
Heat the gallium by placing the container in a warm oven (above 100 deg F) or place the container of gallium in a hot water bath (recommended method)
Place the silicon portion of the gallium spoon mold into an oven set to approximately 120 degrees F and warm it up for about 5 minutes (do not overheat or it will melt)
Remove silicon mold from oven and place into the plexiglass press. Tighten nuts slightly but do not crush the mold.
Fill a small syringe with liquid gallium by putting the end into the gallium and drawing up the plunger.
Push the gallium from the syringe into the mold making sure it fills evenly throughout.
Let sit for 12 hours (this time can be reduced by using the refrigerator).
Is Gallium Safe?
Gallium is a non-toxic metal so it is safe to handle. But it will leave a metallic residue on your hands and on anything it comes into contact with. Also, I wouldn't recommend drinking from the glass of tea or water after gallium has been liquified in the liquid, it is really hard to say what gallium might do to the inside of your body over extended periods of time.
For more Gallium experiments at Beals Science, including how to make a gallium pencil and gallium Christmas Tree ornaments, click HERE.
Free Lesson for Educators
I use the following open inquiry lab with gallium while we are learning about the elements, periodic table, periodic trends, and electron configuration. Through this guided inquiry and open inquiry experiment, students will be exposed to the wonders of gallium while reinforcing their understanding of the key topics in chemistry.
(free pdf download)
Keep on Learning! ~Craig Beals