Can someone me understand what 1b is asking and how to answer it?

The question is basically asking what is happening to the energy (that is in the form of heat) when it is being absorbed by an object.  The energy being absorbed from the heat source is being turned into kinetic energy.  This can be explained by temperature change.  As you add more heat to an object, the temperature rises.  Since temperature is the average kinetic energy of all of the molecules in an object, we can say that as temperature rises so does the kinetic energy of the molecules in the object.  Due to the fact that heat is causing the temperature to increase, we can say that the energy from the heat is being turned into kinetic energy.  

I hope this helps.  Let me know in the comments if anything is unclear.

Answer : option a) 84explanation :

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.