Why do so many stimulant drugs result in a depressed state after ...

[jrubin]

Why do so many stimulant drugs result in a depressed state after an initial high?
 
  A) These stimulant drugs are metabolized into compounds that block excitatory receptor sites.
  B) Many of these drugs are mixtures of both the drug and a second chemical that is the structural mirror image of the drug. After the effect of the drug has worn off, the effect of the mirror image begins to take over.
  C) The body of the user simply runs out of energy in trying to keep up with the artificially induced excited state.
  D) Blocking the re-uptake of excitatory neurotransmitters has the long term effect of decreasing the concentration of neurotransmitters within the synaptic cleft.

Question 2

Is it at all possible for a hydrogen nucleus to emit an alpha particle?
 
  A) yes, because alpha particles are the simplest form of radiation
  B) no, because it would require the nuclear fission of hydrogen, which is impossible
  C) yes, but it does not occur very frequently
  D) no, because it does not contain enough nucleons

[234sdffa]

Answer to Question 1

D

Answer to Question 2

D

[jrubin]

Gracias!

[Kedrick2014]

Excellent