what is the electrical charge of the nucleus of an atom that has 12 protons and 12 neutrons and 12 electrons

Neutral.

Explanation:

Protons have a positive charge. In this problem there are 12.

Electrons have a negative charge. In this problem there are 12.

Neutrons have a neutral charge that isn't relevant tot the overall charge, it can be ignored.

#protons - #e- = charge

12 - 12 = 0

The protons and electrons balance each other out, resulting in a 0 net charge. This means the atom has a neutral charge.

answeridentity;

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.