Covalent Bonds

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Covalent Bonding

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Key Questions

  • The chemical bonds which are formed by sharing valence electrons between two or more non-metals only are called covalent bonds.
    Covalent bonds can be divided into three types based on how many pairs of electrons are being shared between the atoms -

    • SINGLE COVALENT BOND - The covalent bonds in which only 1 pair of valence electrons are shared between atleast two atoms are known as single covalent bonds.
      For example,
      enter image source here
      So, in the image above you can see a single pair of electrons being shared between two hydrogen atoms.
    • Double covalent bonds - The covalent bonds in which two pairs of valence electrons are shared between atleast two atoms are known as double covalent bond.
      For example,
      enter image source here
      In this image don't get confused by the two shells. Only focus on the valence shell ie. the last shell and you will be able to find out that three pairs of valence electrons are being shared.
    • Triple covalent bonds - The covalent bonds in which three pairs of valence electrons are shared between atleast two atoms are known as triple covalent bond.
      For example,
      enter image source here
      In this image too, focus only on the last shell and you will be able to see three pairs of electrons being shared between two nitrogen atoms.
  • Answer:

    They share a valence electron.

    Explanation:

    I'm not sure if this is as much detail as you need, but here goes. In an ionic bond, electrons are transferred completely from one atom to another. The bond is then formed based on the attraction between the positive atom (electron giver) and negative atom (electron receiver). In covalent bonds, the electrons in the outer orbit are shared between the two atoms rather than becoming the "property" of another atom.

    An example of this is hydrogen gas, #H_2# . Instead of creating #H^-# and #H^+# , they share elctrons so that their outer orbits are both filled, creating a stable molecule.

  • In an ionic bond, one atom transfers electrons to the other. In a covalent bond, the two atoms share electrons.

    Ionic Bonds

    In an ionic bond, the more electronegative atom takes atom takes electrons from the other atom. The electronegativity difference must be greater than 1.6 for this to happen.

    www.geo.arizona.edu

    For example, an Na atom can get a complete valence shell by losing an electron, A Cl atom can get a complete shell by gaining an electron.

    The Na transfers an electron to a Cl, forming Na⁺ and Cl⁻ ions.

    The ionic bonds consist of the electrostatic attractions between the oppositely charged ions.

    Covalent Bonds

    In covalent bonding, the two atoms share the valence electrons between them to get to stable octet.

    upload.wikimedia.org

    For example, the electronegativities of C and H are quite close, so one atom cannot take an electron from the other.

    The atoms are forced to share electrons. C needs four electrons to complete its valence shell, and H needs one electron.

    So four H atoms each share their one electron with a C atom. The compound formed is CH₄.

    The C atom now has eight electrons in its valence shell, and each H atom has two electrons. Each has a complete valence shell.

    The covalent bonds consist of the shared electron pairs between the nuclei.

Questions

  • Double-check the answer
    1 month ago