C. Protons
Protons are subatomic particles found in the nucleus and carry positive electrical charge.
a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures.
"the crucible tipped and the mold filled with liquid metal"
a situation of severe trial, or in which different elements interact, leading to the creation of something new.
"their relationship was forged in the crucible of war"
The Octet rule is a general rule of thumb that applies to most atoms. Basically, it states that every atom wants to have eight valence electrons in its outermost electron shell.
Stirring this is because the three elements are factors affecting dissolving of a solvent. Eg temprature affects in hotness or coldness, Particle size affects whether it is big or small while quantity of soluble affects by the amount