Classify a soil profile based on whether it is mature or immature.

Mature soil has a well developed soil profile indicating environmental conditions have been relatively stable over an extended time span.

Immature soil lacks horizons altogether, the soil building has been going on for only a short time, and it is characteristic of steep slopes where erosion continually strips away the soil, preventing full development.

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.