Two different atoms have four protons each and the same mass. However, one has a positive charge while the other is neutral. Describe what each atomic structure could be, listing the possible number and location of all subatomic particles.

Below.

Explanation:

The neutral atom which had 4 protons in the nucleus is beryllium (Be) with atomic structure 1s^2s^2.

It has 4 electrons, the 2 s^2 are valency electrons, and the main isotope has 5 neutrons to give a mass number of 9.

When combining with other elements, for example chlorine, to form the salt BeCl2 the Be forms the Be2+ ion ( positive charge of 2).

The atomic structure will be the same as for that of Be except that there will only be 2 electrons, the 1s^2 electrons.

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.