Question 1: Newtonian. It refers to work of Newton. Light, electrical and chemical energies are different forms of energy.
Question 2: Nuclear power plants. Heat , Sunlight and energy in atoms are not nuclear energies.
Question 3: Batteries. the other two are examples of mechanical energy. But batteries are examples for chemical energy.
210 Pb ---> -ie + 210 B:
84 8.3
Here we can say that there is no external torque on this system
So here we can say that angular momentum is conserved
so here we will have

now we have



similarly let the final distance is "r"
so now we have


now from above equation we have


so final distance is 0.04 m between them