Describe the difference between a soil horizon and a soil profile

Soil profile includes all the sections/ horizons of the vertical soil depth from top to bottom including the transitions from one horizon to another. A soil horizon is a distinct layer/section of soil with more or less the same texture. Therefore, a soil profile is made of soil horizons.  

nah.   i'm just sleepy.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.