Question

The electronic configuration of an element is 2,8,2. The hydroxide of this element can produce ______ hydroxyl ions per molecule.

• A. 3
• B. 2
• C. 1
• D. 4

Hint:

The number of ionizable OH^- ions in a base is known as its acidity. Therefore, Magnesium hydroxide is a diacidic base.

Answer 1

The Correct Option is B

The given electronic configuration of an element is 2,8,2. Let us determine which element this configuration represents and how many hydroxyl ions its hydroxide can produce per molecule.

1. The electronic configuration 2,8,2 corresponds to the element Magnesium (Mg), which is located in the second group of the periodic table. It has an atomic number of 12.
2. Magnesium forms the hydroxide compound Mg(OH)₂. This indicates that magnesium hydroxide consists of one magnesium ion Mg²⁺ and two hydroxide ions (OH^-).
3. Since Magnesium loses two electrons to form a Mg²⁺ ion, each Mg(OH)₂ molecule supplies two hydroxide ions (OH^-).

Thus, the hydroxide of this element, Mg(OH)₂, can produce 2 hydroxyl ions per molecule.

Hence, the correct answer is 2.