CHEMISTRY GUIDE

Topic 2.6   PROPERTIES OF GROUP II ELEMENTS The elements of group II are known as the alkali earth metals . All of these elements are reactive metals. Magnesium and calcium are abundant in the earth's crust. The others are relatively rare. Group II elements have the outer shell configuration ns 2 . 1.         Properties of individual atoms a)         atomic size On descending a group, the number of shells increases. Therefore the outer shells are more shielded from the nucleus, are less closely held and move further away. Therefore the size of the atoms increases down group II . b)         first ionisation energies On descending a group, the number of shells increases. Therefore the outer shells are more shielded from the nucleus, are les...