In group 15 of the Periodic Table, the elements, nitrogen 7N , phosphorus 15P , arsenic 33As , antimony 51Sb and bismuth 83Bi are present. The atomic covalent and ionic radii in a particular oxidation state of the elements of nitrogen family group 15 are smaller than the corresponding elements of the carbon family group There is a considerable increase in covalent radius from N to P. However, from As to Bi, only a small increase is observed. Group 15 elements are more electronegative than group 14 elements. Electronegativity decreases on moving down the group from N to Bi.
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In group 15 of the Periodic Table, the elements, nitrogen 7N , phosphorus 15P , arsenic 33As , antimony 51Sb and bismuth 83Bi are present. The atomic covalent and ionic radii in a particular oxidation state of the elements of nitrogen family group 15 are smaller than the corresponding elements of carbon family group There is a considerable increase in covalent radius from N to P. However, from As to Bi, only a small increase is observed.
Group 15 elements are more electronegative than group 14 elements. Electronegativity decreases on moving down the group from N to Bi. All elements of group 15 form gaseous hydrides of the type MH3. Thus, NH3 is the strongest base. N cannot form NX5 because of non-availability of d-orbitals. Bi cannot form a BiX5 because of reluctance of 6s electrons of Bi to participate in bond formation. Nitrogen forms a number of oxides. II Group 16 Elements 9. The elements have the electronic configuration ns2np4 for their valence shells.
The first element of the group 16 differs in its chemical behaviour from that of other members of the group due to its small size and high electronegativity.
The metallic character increases with increase in atomic number. The first four elements are non- metallic in character. Atomic and ionic radii increases from top to bottom, due to increase in the number of shells. Ionisation enthalpy decreases down the group, due to increase in size.
Elements of group 16 have lower ionisation enthalpy values as compared to group 15 in the corresponding periods. This is due to the fact that group 15 elements have extra stable half-filled p-orbital electronic configurations.
Oxygen has less negative electron gain enthalpy than sulphur due to compact nature of oxygen atom. Within the group, electronegativity decreases with increase in atomic number. The tendency for catenation decreases as we go down the group.
All the elements of the group form volatile ,hydrides. This is evident in their boiling point. Down H20 has abnormally high b. All the elements of group 16 form binary halides. Among the oxo-acids of S, sulphuric acid is most important. They exist only in aqueous solutions or in the form of their salts. III Group 17 Elements Electronic configuration is ns2 np5 for valence shells. Halogens have the smallest atomic radii in their respective periods due to maximum effective nuclear change.
The first ionisation energies are relatively high but decreases down the group. F is the, most electronegative element known. Electronegativity decreases down the group.
Halogens are good oxidising agfents. The oxidising power decreases down the group. Acid strength decreases down the group. In group 18 of the Periodic table, elements helium 2He , neon 10Ne , argon 18Ar , krypton 36Kr , xenon 54Xe and radon 86Rn are present. They are collectively called as noble gases. Noble gases are located at the end of each period. Their valence shell orbitals are fully occupied. They are monoatomic and are sparingly soluble in water. Xe03 is trigonal pyramidal in shape whereas XeOF4 is square pyramidal.
Uses: a He is a non-inflammable gas, lighter than air, therefore, used in filling balloons for meteorological observations.
P – Block Elements Class 12 Notes
Download revision notes for The p-Block Elements class 12 Notes and score high in exams. These are the The p-Block Elements class 12 Notes prepared by team of expert teachers. The revision notes help you revise the whole chapter 7 in minutes. Revision notes in exam days is one of the best tips recommended by teachers during exam days. General electronic configuration of p-block elements: The p-block elements are characterized by the ns2np valence shell electronic configuration. Representative elements: Elements belonging to the s and p-blocks in the periodic table are called the representative elements or main group elements. Inert pair effect: The tendency of ns2 electron pair to participate in bond formation decreases with the increase in atomic size.
The p-Block Elements class 12 Notes Chemistry
The p-Block Elements Class 12 Notes Chemistry Chapter 7