Answer:
12 %
Explanation:
Produces 15 J of work for input 125 J
15/125 * 100% = 12%
A residue from a gunshot is most likely gun powder, which tells you what kind of bullet was shot and the type of gun that was used to shoot the target/victim/person. Some complications may be that there is more than one gun or weapon which uses that residue, so it may be hard to pinpoint it and the bullet can't really tell you who it is unless there's DNA on the bullet, and the chemicals of the bullet may even destroy evidence.
D. a compound can only be separated into its components by chemical means
