A metallic ion Z2+ with an inert gas structure contains 18 electrons. How proton are contained in this ion?

1 answer

To determine the number of protons (atomic number) in the metallic ion Z2+, we have to understand the meaning of an inert gas structure. An inert gas structure is a stable electron configuration that mimics that of a noble gas.

The noble gas with 18 electrons is argon (Ar). Therefore, the metallic ion Z2+ must have gained two electrons to achieve an inert gas structure, similar to that of argon.

Neutral argon has 18 electrons; therefore, the metallic ion Z2+ has 18 - 2 = 16 electrons.

Since the metallic ion Z2+ has a 2+ charge, it means that it lost two electrons from its neutral state. Therefore, the neutral metallic atom must have had 18 + 2 = 20 electrons.

The proton number (atomic number) of an element is equal to the number of electrons. Therefore, the metallic ion contains 16 protons.

In summary, the metallic ion Z2+ has an atomic number of 16.