Answer:
Option A: atomic number = 26, atomic mass = 56, net charge = 3+
Explanation:
Every atom has the same number of electrons as protons. This means that the atom is electrically neutral. If the atom gains or loses electrons that balance is lost ant the atom becomes an ion. For example an isolated iron atom has 26 protons into the nucleus. In order to be electrically neutral, 26 electrons must be moving in its orbitals.
If electrons are lost there will be an excess of protons over electrons, it means an ion with postive charge is formed. These kind of ions are called cations.
If electrons are gained there will be an excess of electrons over protons. In this case the ion formed is called an anion, which is an ion negatively charged.
On the other hand, atomic mass is defined as the sum of its number of protons and neutrons. The number of protons present in the atoms of a given element is always the same (all the iron atoms have 26 protons into the nucleus). However, the number of neutrons may vary in the iron atoms. Some of them have 30 neutrons. But there are other iron atoms having 28 or 31 neutrons. Atoms with the same atomic number but different numbers of neutrons are said to be isotopes.
In this current example the number of protons doesn't match with the number of electrons. It means that the atom is not electrically neutral and we have an iron cation. To know what the net charge is we substract the number of electrons (23) from the number of protons (26).
