Final answer:
Marijuana is an example of a Schedule I drug at the federal level, which means it's considered to have a high potential for abuse and no accepted medical use, despite some states legalizing it.
Step-by-step explanation:
An example of a Schedule I drug at the federal level is marijuana. Schedule I drugs are classified as substances with a high potential for abuse, no currently accepted medical use in treatment in the United States, and a lack of accepted safety for use under medical supervision. Although opium, heroin, fentanyl, morphine, oxycodone, Vicodin, and methadone are all controlled substances, they are not all Schedule I drugs as some are used medically. Cocaine, morphine, and amphetamine are actually classified under different schedules because they have accepted medical uses; for instance, morphine and amphetamines are Schedule II drugs, and cocaine is a Schedule II drug as well.In terms of public policy, the federal-level scheduling has in some cases conflicted with state law. For instance, marijuana has been legalized for recreational use in certain states, despite being a Schedule I drug federally. This has led to a complex legal landscape where the same substance could have drastically different legal statuses across state lines and in comparison with federal law.