The nuclear reaction that occurs by combining two or more lighter atoms into a larger one is called what?
a. nuclear fusion
b. nuclear fission
c. beta emission
d. alpha emission

The nuclear reaction that occurs by combining two or more lighter atoms into a larger one is called nuclear fusion. As a result of this reaction a huge amount of energy is released.  
Nuclear fission is the opposite process of nuclear fusion when the atom splits into several smaller atoms.

Ch4 is nonpolar and insoluble in water. since all of the hydrogen atoms are evenly spread around the carbon atom even through the c h bond is polar all the poles cancel each other out.

Compound with sulfer  is bright red