It seems like you have a list of questions related to chemistry and physics. Here are the answers to your questions:
Radiation
Exothermic, there is a large amount of energy released to the surroundings.
It was energy put into the solid in order to make the particle reach activation energy to break apart.
Energy is always conserved, but can change forms between materials.
Combustion, energy out, exothermic
Add a catalyst, increase the temperature, increase the surface area, increase the concentration.
The remaining reactants will move to form additional products.
For question 8 and 9, I need more information about the elements A, B and C to solve them.
For question 10, if Cadmium-116 were to spontaneously undergo alpha decay that released two alpha particles and 4 gamma particles, the resulting nuclide would be Palladium-112.
For question 11, according to the EPA and monitored by the CDC, the most likely measure of acceptable limits of lead (Pb) in water intended for human consumption is 15 µg/L.
For question 12, I am not sure which location you are referring to. Can you please clarify which location you are asking about?