“A dream. It’s perfect”: Helium discovery in northern Minnesota may be biggest ever in North America::For a century, the U.S. Government-owned the largest helium reserve in the country, but the biggest exporters now are in Russia, Qatar and Tanzania. With this new discovery, Minnesota could be joining that list.
The balloon + helium has to be lighter than the (couple of liters of) air it displaces.
He Density (at STP) 0.1786 g/L
The density of air at sea level is about 1.2 g/L
Another interesting factoid about rare elements: Very little nickel is found in the Earth’s crust. Most nickel has arrived on Earth from meteors. Usually mixed with iron, which held-back the arrival of the iron-age.