1. Alkaline Oxides:
* When these metals react with water, they form hydroxides which are strongly alkaline (basic) in nature. This is where the term "alkaline" originates.
* Their oxides, formed by reaction with oxygen, are also alkaline.
2. Earthy Nature:
* The early alchemists noticed that many of these metals, like magnesium and calcium, occur naturally in rocks and minerals, which they referred to as "earths."
* This "earthy" nature contributes to the name "alkaline earth metals."
3. Reactivity:
* While less reactive than the alkali metals (group 1), alkaline earth metals are still quite reactive, especially with water. This reactivity is due to their two valence electrons, making them readily willing to donate electrons to form ionic bonds.
4. Properties:
* These metals share a common set of properties including:
* They are silvery-white, lustrous metals.
* They are good conductors of heat and electricity.
* They have relatively low densities.
* They are harder and stronger than alkali metals.
In summary, the term "alkaline earth metals" reflects the combination of their alkaline oxides, their historical association with "earths," and their unique chemical reactivity and physical properties.
