What process is responsible for building successive fossil layers on earth

The process that is responsible for building successive fossils layers on earth is called DEPOSITION.
Deposition refers to the process by which sediments are added to a particular land form. There are different types of sediments and they are made up of different elements. A sediment can be in form of rocks and mineral debris, a precipitate formed from dissolution of a mineral in water or remains of other plants and animals. As these sediments are added to the foundational fossils layers, they form deposits which result in building up of successive layers.

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf