Final answer:
The element X in the ion X2+ with 36 electrons is strontium (Sr), and the ion is Sr2+ with 38 protons.
Step-by-step explanation:
To identify the element X in the ion X2+ with 36 electrons, we must consider that the number of protons in an atom defines the element's identity and does not change when an atom becomes an ion. Since the ion has a 2+ charge, this means there are two more protons (38 in total) than electrons.
Using the periodic table, we can determine that the element with an atomic number of 38 is strontium (Sr). Hence, the ion is Sr2+, the strontium cation, with 38 protons, 36 electrons, and a mass number dependent on the specific isotope of strontium.