What does the scientist mean when he says that white blood cells would not be "fast enough or smart enough if we hadnt whipped them along by a prior immunization" HELP PLEASE I NEED TO TURN IT IN TODAY!

the answer is a. co2, this would be colder than the : )

explanation:

the answer your looking for is c).

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.