Hydrogen gas is very flammable and yields explosive mixtures with air and oxygen. The explosion of the mixture of hydrogen and oxygen is quite loud. Tests should be made prior to the demonstration to adjust the total volume in the balloons so that the sound of the explosion is tolerable in the room.
How long does cooked beef stew last in the freezer? Properly stored, it will maintain best quality for about 4 to 6 months, but will remain safe beyond that time. The freezer time shown is for best quality only - cooked beef stew that has been kept constantly frozen at 0â will keep safe indefinitely.
1 Cooked ground beef will usually stay good for 3 to 4 days in the fridge and 3 months in the freezer.  How to tell if ground beef is bad? The best way is to smell and look at the ground beef: signs of bad ground beef are a sour smell, dull color and slimy texture; discard any ground beef with an off smell or appearance.