Final answer:
Ping-Pong balls are highly flammable due to their composition of nitrocellulose and camphor that requires a low activation energy to burn, and their large surface area to volume ratio facilitates rapid combustion.
Step-by-step explanation:
Ping-Pong balls are highly flammable because they are composed primarily of celluloid, which is a type of nitrocellulose and camphor. The chemical structure of celluloid makes it very flammable. When the reactants in the celluloid are exposed to sufficient activation energy, typically presented in the form of heat or flame, the chemical bonds break down rapidly resulting in a fast and exothermic reaction.
Furthermore, just as kindling is used to start a fire due to its increased surface area, the relatively large surface area to volume ratio of a Ping-Pong ball can facilitate a quicker reaction rate. In the presence of oxygen, the initial combustion reaction generates enough heat to sustain the reaction, making Ping-Pong balls highly flammable. This is an example of understanding the dangers of substances with a low activation energy for combustion, much like flour dust explosions in mills or the use of shape charges to compress plutonium in nuclear devices.