Why are scientific explanations subject to change? A) Scientists always need better technology. B) Scientific explanations are only a best guess. C) New scientific explanations are always better than old explanations. D) Scientific explanations are based on new observations and making sense out of those observations.

D. Scientific explanations are based on new observations and making sense out of those observations.

Explanation:

(don't quote me)

i belive it is water

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.