The oxidation number for ions from the alkaline earth metal family is +2.
Understanding Alkaline Earth Metal Ions
Alkaline earth metals are elements found in Group 2 of the periodic table. These metals, including beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra), are characterized by having two electrons in their outermost s-orbital. To achieve a stable electron configuration—like that of the noble gas preceding them—these atoms readily lose both of these valence electrons. When an atom loses electrons, it forms a positively charged ion, known as a cation. The loss of two electrons results in an ion with a net charge of +2, and therefore, an oxidation state of +2.
This consistent behavior makes their oxidation state highly predictable in compounds. They almost exclusively form ions with a +2 charge when participating in chemical bonds, losing both valence electrons to achieve a stable electron configuration.
Examples of Alkaline Earth Metals
Here are some common alkaline earth metals that form ions with a +2 oxidation state:
- Beryllium (Be)
- Magnesium (Mg)
- Calcium (Ca)
- Strontium (Sr)
- Barium (Ba)
Summary Table of Oxidation Numbers
The following table summarizes the typical oxidation state for ions of the alkaline earth metals:
| Element | Symbol | Typical Ion | Oxidation Number |
|---|---|---|---|
| Beryllium | Be | Be²⁺ | +2 |
| Magnesium | Mg | Mg²⁺ | +2 |
| Calcium | Ca | Ca²⁺ | +2 |
| Strontium | Sr | Sr²⁺ | +2 |
| Barium | Ba | Ba²⁺ | +2 |
| Radium | Ra | Ra²⁺ | +2 |
For more information on oxidation states and the properties of elements, you can refer to reputable chemistry resources like the Royal Society of Chemistry's periodic table.
