An element's most stable ion forms an ionic compound with chlorine having the formula XCl₂.If the ion of element X has a mass number of 89 and 36 electrons,what is the identity of the element X,and how many neutrons does it have?

Question

Quizplus · Accepted Answer

The element X forms an ion with 36 electrons, which means its atomic number is 36, identifying it as krypton (Kr) in its neutral state. However, since the ion has a mass number of 89 and given that the atomic number (number of protons) for Kr is actually 36, the element in question must be strontium (Sr) because the atomic number fits the electron count for its most stable ion. Strontium's atomic number is 38, but as an ion with 36 electrons, it has lost 2 electrons, indicating it is in a +2 oxidation state, which matches the properties of strontium ions. To find the number of neutrons, subtract the atomic number from the mass number: 89 - 38 = 51 neutrons.

An Element's Most Stable Ion Forms an Ionic Compound with Chlorine