Ncert std 11th chemistry chapter 4 all important notes | Chemical bonding and Molecular Structure#11#chemistryquestions#chemistryexam#chemistrysolved#11th#11thcbse#11thchemistry#chemistrynotes#chemistryquiz#chemistrymcq#chemistrymentor#chemistrymotivation#chemistrymocktest#chemistrymemes#11thclass#std11_gseb#std11thscience#std11th#11thclassphysics#11thclasschemistry#onlineclasses#onlinechemistryclassesbyvipulsir#onlinechemistry#onlinechemistryclass#onlinechemistryhelp#chemistryformulas#chemistryforjee#chemistryfacts#chemistryfamily#chemistryforneet#chemistryfornda#chemistryforall#chemistryforyou#chemistryguide#chemistryguru#chemistrygk#chemistrygururavisir#chemistryknowledge#chemistrykaisesikhe#chemistrykaisesamjhe#chemistrykaiseyadkre#chemistrykaisepdeclass11#chemistrykaisepdeforneet#chemistrykaisepadheclass12#like#share#subscribe#support#onlinechemistryclasses#chemistrybysunilsir#chemistrybykhansir#chemistrybyshekharsir#chemistrybyshekharsir <br /><br /><br /><br /><br />Your searches :-<br />Chapter - 4<br />Chemical bonding and Molecular Structure<br />Some Important Points and Terms of the Chapter<br />1. Lewis dot structures are shorthand to represent the valence electrons of an atom. The structures<br />are written as the element symbol surrounded by dots that represent the valence electrons.<br />2. Covalent Bonds- The bond formed between two atoms by mutual sharing of electrons between<br />them so as to complete their octets or duplets. When two atoms share one electron pair they are<br />said to be joined by a single covalent bond.e.g H₂ If two atoms share two electron pairs of<br />electrons, the covalent bond between them is called a double bond. e.g O₂ If two atoms share<br />three electron pairs of electrons, the covalent bond between them is called a double bond. e.g N₂<br />3. Octet Rule-Kossel and Lewis in 1916 developed an important theory of chemical combination<br />between atoms known as electronic theory of chemical bonding. According to this, atoms can<br />combine either by transfer of valence electrons from one atom to another or by sharing of<br />valence electrons in order to attain their octet. This is known as octet rule.<br />4. Limitations of octet rule-<br />a) Incomplete octet of the central atom: In some compounds the number of electrons surrounding<br />the central atom is less than eight. This is especially the case with elements having less than four<br />valence electrons. Examples- LICI,BeCl₂, BCI,<br />b) Odd-electron molecules: In molecules with an odd number of electrons like nitric oxide, NO and<br />nitrogen dioxide, the octet rule is not satisfied for all the atoms.<br />c) The expanded octet: Elements in and beyond the third period of the periodic table have, apart<br />from 38 and 3p orbitals, 3d orbitals also available for bonding. In a number of compounds of<br />these elements there are more than eight valence electrons around the central atom. This is<br />termed as the expanded octet. Some of examples of such compounds are: PFs, SFG-<br />d) This theory does not account for the shape of molecules.<br />5. Electrovalent bond or Ionic Bond: The che
