chemical bonding

• Covalent bonding occurs between two non-metals, where electrons are shared between atoms to form a stable molecule.
• The metal loses electrons to become a positively charged ion (cation), while the non-metal gains electrons to become a negatively charged ion (anion).
• Ionic compounds are formed when metals react with non-metals.
• <S: Covalent bonds form when atoms share one or more electrons to fill their outer shells and achieve stability.
• Covalent bonds form between two atoms sharing electrons to achieve an octet (8 valence electrons).
• In covalent bonding, there is no transfer or movement of electrons from one atom to another.
• formal charge is extra charge present on atom in any molecule due to gain or loss of electron
• Lewis structures show how many pairs of electrons surround each atom in a molecule.
• Each dot represents a pair of electrons shared by that atom (in lewis dot str.)
• If all the dots are used up, then the Lewis structure is complete.
• The central atom has eight dots around it, indicating its full outer shell.
• In covalent bond each combining atom contributes atleast one electron to the shared pair
• what is ionic or electrovalent bond

  the bond formed as a result of electrostatic force between 2 oppositely charged atoms this atom is mostly formed in between metals and non-metals so they'd be converted into cation or anion
• lattice enthalpy

  the amount of energy required to completely sperate one mole of solid ionic compound into constituent gaseous ion
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  dipole moment

  -it measures the net polarity of any polar covalent bond (mu=q.d)

  -mu=0 (non polar)

  -mu is not zero (polar)
• what is polar and non polar

  polar is when an atom has both charged ends and polar when none of the end is polar
• octet rule

  it was given by kossel lewis in 1961 in which he described in order to have a stable atom we need to complete the octet (8e in lasst shell)and duplet (2e in last shell) i.e they should have noble gas configuration.
• ionisation energy

  amount of energy required to remove an e from outermost shell of an isolated gaseous atom to convert it into cation
• electron gain enthalpy

  energy released when an isolated gaseous atom takes up an e from an anion
• covalent bond (homoatomic and heteroatomic)

  revise
• non polar covalent bond

  the atoms joined by covalent bond are same and those atoms are equally attracted and the shared e pair is equidistant to both of them
• polar covalent bond

  when bond is shared by 2 diff. atoms w diff. electronegativity and gets displaced towards more electronegative atom