A group of students want to investigate the speed of waves through different media. Design an experiment that will compare the speed of a sound wave
or a light wave through three different media. Include a list of materials and the procedures you would follow.

the answer is 75.0%.

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.

diaria maybe go see a doctor about that