Which of the following is a homogeneous mixture?

beef stew

soil

sand and water

salt water

Salt and water
because the salt entirely dissolves in the water until it becomes a uniform solution. The problem with beef stew is that you can differentiate the vegetables from the broth and the beef. The issue with the soil is that you can separate the different kinds of dirt and leaves from each other. The issue with sand and water is that you can pick the sad out of the water. Salt water will be uniform and you will not be able to differentiate pieces of salt from the water because they will be one solution.

Decomposition is the cycle at which bacteria breaks down any organic material into the soil

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