How many protons are in an ion with 86 electrons and a negative 1 charge

85 protons

Explanation:

Atomic number is defined as the number of protons or number of electrons that are present in an atom in an electrically neutral atom.

Atomic number = Number of electrons = Number of protons

Electrons are negatively charged particles which are present around the nucleus and protons are positively charged particles present in the nucleus. Ions are formed when an atom looses or gain electrons.

In an atom, when electrons are lost, the atom gains a positive charge and forms cation. In an atom, when electrons are gained, the atom occupies a negative charge and forms anion.

Thus if an atom has a charge of -1 , it means the atom has gained one electron and thus the electrons were 85 and the protons will also be 85.