Advertisement Upgrade to remove ads


means numbness or deadening


drugs that relieve pain by depressing the central nervous system.


drugs that nn cause makred alterations in normal thought processes,perceptions,and moods.

psychological dependence

the conditioned use of a drug caused by underlying emotional needs

physical dependence

physiological need for a drug brought about by its regular use and characterized by withdrawal sickness when administration of the drug is abruptly stopped


a substance that slows down or depresses the functions of the central nervous system


a range of drugs that stimulate or speed up the central nervous system

anabolic steroid

synthetic compounds that are chemically related to the male sex hormone testosterone

screening tests

a preliminary test used to redue the number of possible identites of an unknown substance


a single test that specifically identifiies a substance

microcrystalline testt

a test that identifies a specific substance based on the color and shape of crystals formed when the substance is mixed with specific reagents


any of several analytical techniques for separating organic mixtures into their components by attraction to a stationary phase by a propelled by a moving phase


to emit visible light when exposed to light of shorter wavelength


type of radiation that gives us a tan and that causes skin cancer


electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves


electrically charged atoms that have gained or lost electrons.


An analytical method for identifying a substance by its selective absorption of different wavelengths of light.

monochromatic light

Single wave length light


A device for isolating individual wavelengths or frequencies of light.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording