I believe the answer is: Stimultant
Consuming stimultant would increase the brain activity in your central nervous system. This would increase thee needs to seek source of excitements or other pleasurable activities, that could cause someone to have low attentions pan and disruptive behaviors.
Answer:
How invisible particles can be observed in outer space. ... We call this invisible mass dark matter since it cannot reflect light. Gravitational effects are only way we can detect its presence.
