Auditory processing disorder (also known as central auditory processing disorder or CAPD) is a condition that makes it hard for kids to recognize subtle differences between sounds in words. It affects their ability to process what other people are saying.
Gallium is a solid metal at room temperature, but it melts in your hands. 00:09. When gallium is in its liquid state, if feels like cold melted solder in your hands. 00:33. Melting gallium onto aluminum makes the aluminum brittle enough to break with your fingers.
The key thing is that you NEED flux when melting metal unless you're doing your melting in an inert-atmosphere furnace and starting with new, non-oxidized metal. For silver, gold, brass, bronze and copper, borax/boric acid is a good flux. For aluminum you need a different flux - check with a casting supply place for what you should use for the particular alloy of aluminum you are melting.