More or less. The outer regions at low density, pressure and temperature would contain the dominant compounds in gaseous form such as methane and ammonia and other hydrogenic gases. The temperatures and pressures continue to increase inwards, allowing some new compounds of these constituents to form, then still further-in these compounds begin to fall apart again under the high temperature and pressures. Following a rather homogeneous, thick region containing the bulk of the planets mass, we approach the planetary core which is believed to contain all of the other elements such as silicon, iron, magnesium, calcium, and so on. The boundary between the core and the 'atmosphere' may be indistinct due to some diffusion of these elements into the inner atmosphere region. There may also be a significant change in the compounds present as you cross this boundary layer since new 'high pressure' phases of common compounds may survive.