You learn that a barrel of the bolts has a mass of 65.2 kg. The mass of the barrel wa: 9.6 kg. How many boxes of bolts are in the barrel?

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

explanation:

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.