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.
While properly cooking and then eating food that had stayed frozen at 0Â°F for years won't necessarily get you sick, you probably won't like how it tastes. So the USDA recommends tossing uncooked roasts, steaks and chops after a year in the freezer, and uncooked ground meat after just 4 months. And frozen cooked meat should go after 3 months. While expired frozen meat may look all right to eat, the safest bet is to mark an expiration date on the meats to keep yourself and carnivores in your family safe from food-borne illnesses. [via BusinessInsider.com]