Representative elements of periodic table
Representative elements of periodic table include both s and p block elements with exceptions of noble gas which form a separate group. The general characteristics of Representative elements are periodic function of their atomic numbers with repeating physical and chemical properties.
The elements to the different electronic arrangement of atoms possess different chemical properties as the number of electrons in an atom are given by the atomic number and not by the atomic mass. The Representative elements of periodic table are based on the atomic number should form the basis of classification of elements in periodic table and not by Mendeleev.
In periodic table they are two S-block and seven P-Block with exception of noble gas group(18).The long form of periodic table has divided into four blocks s, p, b, f . The inclusion of an element in a particular block is linked with the sub shell(or orbital) in which the last electron in an atom is filled. For example, In S-block the last electron is filled in the s-orbital, same in case with the other elements.We can locate the period and block of Representative elements of a periodic table.
The general characteristics of Representative elements of periodic table are:
S block(group 1)
- These are soft in nature and can be cut with the help of knife except the lithium.
- The atoms of alkali metals have the largest size in their respective periods.
- The alkali metals show +1 oxidation state.
- The melting and boiling points of alkali metals are very low
- ll the alkali metals form ionic (electrovalent) compounds.
- The alkali metals are good conductors of heat and electricity.
- The alkali metals and their salts impart a characteristic color to flame
S block(group 2)
- Higher melting points than alkali metals
- Higher boiling points alkali metals
- Higher densities alkali metals
- Harder than the corresponding alkali metals