Which is expected to have high melting point : NH3 , (CH3)3N , PH3 and why​

What type of matter is made of only one kind of atom

The footprints of a dinosaur and the burrow of an ancient shrimp are examples of which kind of fossils

Equal numbers of moles of he(g), ar(g), and ne(g) are placed in a glass vessel at room temperature. if the vessel has a pinhole-sized leak, which of the following will be true regarding the relative values of the partial pressures of the gases remaining in the vessel after some of the gas mixture has effused?