5-O selênio e o enxofre pertencem à família VI A da tabela periódica. Sendo assim, o seleneto e o sulfeto de hidrogênio são representados, respectivamente pelas fórmulas:

a) HSe e HS

b) H 2 Se e HS

c) HSe e H 2 S

d) H 2 Se e H 2 S

e) H 3 Se e H 3 S

Exothermic,  physical change after it is already baked

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