The best answer I could find was when you Google it, that the fuse is of poor quality. I cannot leave you a link, but you can find it for yourself. Put in poor quality fireworks and all sorts of things will pop up. No pun intended.
Answer: b) Less dense
Explanation:
Differences in density is one reason objects float or sink.
An object more dense than the fluid in which it is immersed will sink, while objects less dense than the fluid in which it is immersed will float to the surface.
But objects floats at constant level if the density is equal to the density of the fluid in which it is immersed; it neither rises nor sinks in the fluid in this case.
Answer:
Boron. The answer is boron.
