Artifical fingernails
These are simply one of several kinds of plastic,often polymethylmethacrylate with a suitable glue such as ethylcyanoacrylate to hold them in place.
Fingernail polish and remover
Fingernail polish is a mixture of pigments in a polymer , sometimes nitrocellulose or acrylic in a solvent such as ethyl acetate and butyl acetate(CH3COOC2H5 and CH3COOC4H9) fingernail polish remover is simply acetone (CH3COCH3) or ethyl actate ( CH3COOC2H5) . both of these dissolve the polish and are very volatile . sometimes one or the other is mixed with mineral oil ( saturated hydrocarbons of approximately 10 carbon atoms ) to slow down the evaporation of the substance and allow more working time . care must be taken when using these products because they remove nearly any kind of paint or varnish and dissolve the surface layer of linoleum or most floor tile. You must be very careful not to spill such a product on a vulnerable piece of furniture or floor tile .