(4) 220Fr, known as Francium-220, undergoes alpha decay, which emits an alpha particle, also known as a helium nucleus, which has a charge of +2.
Distillation is the process of separating homogeneous mixtures -and a solution is a homogenous mixture, so this is the correct answer!
A homoogeneous mixture is a mixture in which the elements are mixed so well, that the mixture has a similar composition in all its parts. A heat can be applied to this mixture then to separate the parts - this is destination!
The average atomic mass of the element is the sum of the products of the percentage abundance of isotope and its mass number. Therefore, for atomic mass equal to 58.933, the most abundant isotope is cobalt-59. Thus, the answer is letter C.