Hydrogen to be more precise protium which is an isotope of hydrogen containing one proton and one electron. It is considered to be very stable which explains it's abundance everywhere. However under extreme conditions like in the sun, it undergoes nuclear fusion to form helium. So in conclusion, under normal circumstances Protium is considered to be very stable however under extreme circumstances it is radioactive. Does that answer your question?
Answer: True
Explanation:
Weak electrolytes are those solutions which do not undergo complete dissociation when dissolved in water. The dissociation of weak electrolytes is given by an equilibrium.
Example: 
Strong electrolytes are those solutions which undergo complete dissociation when dissolved in water. The dissociation of strong electrolytes is given by a right arrow.
Example: 
Thus the degree to which various compounds will dissociate in solution varies greatly is true.
Increase, because you need heat to melt a solid to a liquid, so the temperature will have to get greater.