List I | List II | ||
---|---|---|---|
A | Mesozoic Era | I | Lower invertebrates |
B | Proterozoic Era | II | Fish & Amphibia |
C | Cenozoic Era | III | Birds & Reptiles |
D | Paleozoic Era | IV | Mammals |
The group two or alkaline earth metals are s-block elements with two electrons in their s-orbital. They are alkaline earth metals. They are named so because of the alkaline nature of the hydroxides and oxides.
Alkaline earth metals are characterized by two s-electrons. This group of elements includes:
Elements whose atoms have their s-subshell filled with their two valence electrons are called alkaline earth metals. Their general electronic configuration is [Noble gas] ns2. They occupy the second column of the periodic table and so-called as group two metals also.