a) The required conductivity of an n-type silicon sample at T 300 K is to be 10 (-cm)1. What donor impurity concentration is required? What is the electron mobility corresponding to this impurity concentration? (b) A p-type silicon material is required to have a resistivity of 0.20 (-cm). What acceptor impurity concentra-tion is required and what is the corresponding hole mobility

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.