The Periodic Table and bonding The modern periodic

The Periodic Table and bonding The modern periodic table represents the arrangements of elements according to the building up (Aufbau principle), where each element has one electron more than the previous element. The periodic table can be classified in many different ways: -based on the metallic character. Periodic table can be classified into three main categories: metals, nonmetals, and metalloids. The larger grouping is the metals. The nonmetals associated with the living systems. Metalloids conduct heat and electricity better than nonmetals but not as well as metals. -The second set of classifications is based on the horizontal rows (Periods) and vertical columns (Groups).

A group is a vertical collection of elements with the same number of outer electrons. They all have similar chemical properties because they tend to lose or gain the same number of electrons in reactions. These kinds of similarities are strongest in the alkali metals in Group l. A and in the halogens in Group 7 A. The periodic table contains the following important groups: • Column I is a groups of elements that have one electron on their outer shell, s - orbital. Group one elements are called the alkaline metals. • Elements in the groups from l. A to 7 are called representative metals • Elements in column II, called the alkaline - earth metals, all have 2 electrons in their outer s-orbital shells.

• Groups III, IV, V, VI, and VII all have the same number of outer shell electrons as the group number. • Group VII elements are known as the halogens. • Group VIII elements are all characterized by having completely filled p - orbital shells with 8 electrons total in their outermost s - and p shells. This group is known as the noble gas or inert gases , inert because these elements do not combine with themselves or with any other element under normal conditions. • Transition metals occur between the (Group II) and Group III , with partially filled d - orbital.

• Elements also could be classified according to their last orbital, such as s-block, p-block, d-block and f-block elements. The series from La to Lu is known as the lanthanides and these elements are called the Rare Earth Elements. Another discontinuity occurs at element 89, Ac where the 5 f - orbitals begin to be filled, starting with the element. The elements 89 through 103 are referred to as the Actinides. For example, sodium, Na, is in row three and in Group 1 A. Sodium has one outer electron and ten core electrons. The outer electron is in the 3 s subshell, n = 3. The electron configuration for this outer electron is 3 s 1