Which atoms could join together to form a molecule of an element?
This chart shows four atoms, labeled W, X, Y, and Z.
These atoms can combine with each other to form
molecules.
O W and X
O X and Y
O W and Z
O Y and Z
Atom
w
Х
Y
Z
Element
oxygen
hydrogen
carbon
oxygen

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.

it is the most commonly accepted one

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.