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 How long does cooked roast beef last in the freezer for safety purposes? 2  The freezer time shown is for best quality only â foods kept constantly frozen at 0Â° F will keep safe indefinitely.