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

A neutral atom has equal number of protons and electrons while an ion does not.

The neutral atom has atomic structure 2,7 while the atom with a negative charge has atomic structure 2,8.

An atom is neutral when the number of protons and electrons are equal. If an atom has nine protons in the nucleus, then it should have nine electrons in the orbits with a structure of 2,7 in the respective first and second shells.

For the atom that has gained one electron and has a negative charge, there are nine protons and ten electrons arranged in the order 2,8 in the two shells.

the objects have the same charge.