15) a force of 200 n is exerted on an object of mass 40 kg that is located on a sheet of perfectly smooth ice.
a. calculate the acceleration of the object. flm = 200 ong e m/s2
b. if a second object identical to the first object is placed on top of the first object, what
acceleration would the 200 n force produce?

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.