Travel 4.
Waves are energy in motion in some medium. Which is the best
explanation of how waves get their energy?
A. Waves get their energy from the wind.
B. Waves get their energy from random motions of the molecules of
their medium.
C. Waves get their energy from an original or continuing
disturbance of the medium.
D. Waves get their energy from seismic events such as offshore
earthquakes.

the answer is 0.42 is that is an option. this question provides no info

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.