Basic Concepts of Inorganic Chemistry, 2nd Edition

11

Group - 2 (II_A) [Be, Mg, Ca, Sr, Ba, Ra]

The group 2 elements are called alkaline earth metals. All are solids and have crystal structure. But unlike group 1 metals, crystal structures are not similar.

The valence shell of the metals is ns². The metallic bond strength in these metals are stronger (2 valence electrons) than alkalimetals (one valence electron). The metals are, therefore, harder than alkali metals (Be is hard enough to scratch glass). But the hardness decreases with increasing atomic size.

Beryllium compounds are toxic and affect lung tissue. All isotopes of radium are radio active,

that is, 226 — Ra is α active.

Radium was ...