The electromagnetic waves with the shortest wavelengths and the highest frequencies are called: a. ultrasonic waves. c. x-rays. b. microwaves. d. gamma rays. select the best answer from the choices provided a b c d

The answer would be  D) gamma rays

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