What does the X represent in the following symbol? 80
X
35
A. Mercury (Hg)
B. Chlorine (CI)
C. Scandium (Sc)
D. Bromine (Br)

Nonmetals usually react by gaining electrons

The answer should be vaporization 

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   

Radioactive fallout is a result of the fission creation used to ignite the thermonuclear fusion reaction.