What is the identity of the element X in the following ions? (a) X²⁺, a cation that has 36 electrons (b) X⁻, an anion that has 36 electrons

The atomic number of an element is defined as the number of protons in its nucleus, which also equals the number of electrons in a neutral atom. In this question, the identity of element X can be determined by analyzing the number of electrons in its ionic forms. For X²⁺ with 36 electrons, the neutral atom must have 38 protons, indicating an atomic number of 38, which corresponds to strontium.

Ionic charge refers to the electrical charge that an atom or molecule carries due to the loss or gain of electrons. A cation, like X²⁺, has a positive charge because it has lost electrons, while an anion, like X⁻, has a negative charge due to the gain of electrons. Understanding how these charges relate to the number of electrons helps in identifying the element in question.

Electron configuration describes the distribution of electrons among the various orbitals of an atom. For element X, knowing its atomic number allows us to write its electron configuration, which can provide insights into its chemical properties and behavior. In this case, both ions X²⁺ and X⁻ share the same electron count, but their configurations differ due to the loss or gain of electrons, leading to the identification of the element.