Answer:
The correct answer is Barium (Ba)
Explanation:
A neutral atom - without charge- has the same number of protons and electrons. The atomic number - that is, the number of protons - is the identity of the element.
If an atom has 2+ charge, it has lost 2 electrons. Since it has 54 electrons, the atomic number of the element is: 54 + 2 = 56.
From the Periodic Table, the element with atomic number 56 is Barium (Ba).