Think about a construction crane moving a steel beam. Where does the energy used to complete the task come from? What evidence do you have that the amount of energy involved in the crane example is different from that in the wind-up toy example?

c, liquids evaporate, creating a gas

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.