The Adam Bomb has two halves that clip together to form a bomb. If you put powder inside it simulates an explosion on impact. The Adam Bomb has four clips on the inside that easily release on impact. Most of the energy gets dissipated and then the bomb can then be reused. Soft grass will make them last longest, but usually a few high altitude drops on asphalt will cause the tip to split a little so be careful where you place you targets.
You can experiment with different inert ingredients. In this picture a wide variety of spices that had gone stale are shown to demonstrate that your imagination can go wild with regards to making a good simulated explosion. I have found that Rice Flour available at Asian Supermarkets to make the best explosion simulations. Better then Talc or Ash.
Low altitude bomb runs on asphalt can tear off the fins. I have repaired may with super glue and tried to stay away from low high speed drops. The best angle of attack is to shallow dive from 80 feet up and drop at about 55′ to 60′. Be aware that you can get target fixation and crash your plane if you are too low when you push the button to release. Ask me how I know? That is why 75′ is a good starting number for pulling the trigger. The bombs have enough altitude to hit more on their nose which saves wear and tear on you ordnance. The poof is more spectacular too. Low and they just dribble out the powder. Higher up and they let out a smack and an explosion that looks the part.