Alkaline Earth Metals: Elements of the Second Main Group

All elements of this group, from beryllium to barium, were discovered about 200 years ago, and radium was also discovered at the end of the nineteenth century. Magnesium, calcium, and barium are very common in the earth’s crust; on the other hand, beryllium and strontium are much rarer. Radium is one of the decay products of naturally occurring uranium and is therefore always present in uranium ores, albeit only in the smallest traces. The elements of this group are all metals, but they show clear gradations of their properties. The “true” alkaline earth metals calcium, strontium, barium, and radium show the typical high reactivity towards water, acids, and non-metals, whereas this is only weakened in magnesium and is seen to a much lesser extent in beryllium.