What is "single bond"

Bond \Bond\ (b[o^]nd), n. [The same word as band. Cf. Band, Bend.]

1. That which binds, ties, fastens, or confines, or by which anything is fastened or bound, as a cord, chain, etc.; a band; a ligament; a shackle or a manacle.

   Gnawing with my teeth my bonds in sunder, I gained my freedom.
   --Shak.

2. pl. The state of being bound; imprisonment; captivity, restraint. ``This man doeth nothing worthy of death or of bonds.''
   --Acts xxvi.

3. A binding force or influence; a cause of union; a uniting tie; as, the bonds of fellowship.

   A people with whom I have no tie but the common bond of mankind.
   --Burke.

4. Moral or political duty or obligation.

   I love your majesty According to my bond, nor more nor less.
   --Shak.

5. (Law) A writing under seal, by which a person binds himself, his heirs, executors, and administrators, to pay a certain sum on or before a future day appointed. This is a single bond. But usually a condition is added, that, if the obligor shall do a certain act, appear at a certain place, conform to certain rules, faithfully perform certain duties, or pay a certain sum of money, on or before a time specified, the obligation shall be void; otherwise it shall remain in full force. If the condition is not performed, the bond becomes forfeited, and the obligor and his heirs are liable to the payment of the whole sum.
   --Bouvier.
   --Wharton.

6. A financial instrument (of the nature of the ordinary legal bond) made by a government or a corporation for purpose of borrowing money; a written promise to pay a specific sum of money on or before a specified day, given in return for a sum of money; as, a government, city, or railway bond.

7. The state of goods placed in a bonded warehouse till the duties are paid; as, merchandise in bond.

8. (Arch.) The union or tie of the several stones or bricks forming a wall. The bricks may be arranged for this purpose in several different ways, as in English bond or block bond (Fig. 1), where one course consists of bricks with their ends toward the face of the wall, called headers, and the next course of bricks with their lengths parallel to the face of the wall, called stretchers; Flemish bond (Fig.2), where each course consists of headers and stretchers alternately, so laid as always to break joints; Cross bond, which differs from the English by the change of the second stretcher line so that its joints come in the middle of the first, and the same position of stretchers comes back every fifth line; Combined cross and English bond, where the inner part of the wall is laid in the one method, the outer in the other.

9. (Chem.) A unit of chemical attraction between atoms; as, oxygen has two bonds of affinity. Also called chemical bond. It is often represented in graphic formul[ae] by a short line or dash. See Diagram of Benzene nucleus, and Valence. Several types of bond are distinguished by chemists, as double bond, triple bond, covalent bond, hydrogen bond.

10. (Elec.) A heavy copper wire or rod connecting adjacent rails of an electric railway track when used as a part of the electric circuit.

11. League; association; confederacy. [South Africa]

    The Africander Bond, a league or association appealing to African, but practically to Boer, patriotism.
    --James Bryce.

    Arbitration bond. See under Arbitration.

    Bond creditor (Law), a creditor whose debt is secured by a bond.
    --Blackstone.

    covalent bond, an attractive force between two atoms of a molecule generated by the merging of an electron orbital of each atom into a combined orbital in the molecule. Such bonds vary in strength, but in molecules of substances typically encountered in human experience (as, water or alcohol) they are sufficiently strong to persist and maintain the identity and integrity of the molecule over appreciable periods of time. Each such bond satisfies one unit of valence for each of the atoms thus bonded. Contrasted with hydrogen bond, which is weaker and does not satisfy the valence of either atom involved.

    double bond, triple bond, a covalent bond which involves the merging of orbitals of two (or three) electrons on each of the two connected atoms, thus satisfying two (or three) units of valence on each of the bonded atoms. When two carbon atoms are thus bonded, the bond (and the compound) are said to be unsaturated.

    Bond debt (Law), a debt contracted under the obligation of a bond.
    --Burrows.

    hydrogen bond, a non-covalent bond between hydrogen and another atom, usually oxygen or nitrogen. It does not involve the sharing of electrons between the bonded atoms, and therefore does not satisfy the valence of either atom. Hydrogen bonds are weak (ca. 5 kcal/mol) and may be frequently broken and reformed in solution at room temperature.

    Bond of a slate or lap of a slate, the distance between the top of one slate and the bottom or drip of the second slate above, i. e., the space which is covered with three thicknesses; also, the distance between the nail of the under slate and the lower edge of the upper slate.

    Bond timber, timber worked into a wall to tie or strengthen it longitudinally.

    Syn: Chains; fetters; captivity; imprisonment.

n. (context chemistry English) A covalent bond in which one electron pair is shared between two atoms.

In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons. That is, the atoms share one pair of electrons where the bond forms. Therefore, a single bond is a type of covalent bond. When shared, each of the two electrons involved is no longer in the sole possession of the orbital in which it originated. Rather, both of the two electrons spend time in either of the orbitals which overlap in the bonding process. As a Lewis structure, a single bond is denoted as AːA or A-A, for which A represents an element (Moore, Stanitski, and Jurs 329). In the first rendition, each dot represents a shared electron, and in the second rendition, the bar represents both of the electrons shared in the single bond.

A covalent bond can also be a double bond or a triple bond. A single bond is weaker than either a double bond or a triple bond. This difference in strength can be explained by examining the component bonds of which each of these types of covalent bonds consists (Moore, Stanitski, and Jurs 393).

Usually, a single bond is a sigma bond. An exception is the bond in diboron, which is a pi bond. In contrast, the double bond consists of one sigma bond and one pi bond, and a triple bond consists of one sigma bond and two pi bonds (Moore, Stanitski, and Jurs 396). The number of component bonds is what determines the strength disparity. It stands to reason that the single bond is the weakest of the three because it consists of only a sigma bond, and the double bond or triple bond consist not only of this type of component bond but also at least one additional bond.

The single bond has the capacity for rotation, a property not possessed by the double bond or the triple bond. The structure of pi bonds does not allow for rotation (at least not at 298 K), so the double bond and the triple bond which contain pi bonds are held due to this property. The sigma bond is not so restrictive, and the single bond is able to rotate using the sigma bond as the axis of rotation (Moore, Stanitski, and Jurs 396-397).

Another property comparison can be made in bond length. Single bonds are the longest of the three types of covalent bonds as interatomic attraction is greater in the two other types, double and triple. The increase in component bonds is the reason for this attraction increase as more electrons are shared between the bonded atoms (Moore, Stanitski, and Jurs 343).

Single bonds are often seen in diatomic molecules. Examples of this use of single bonds include H, F, and HCl.

Single bonds are also seen in molecules made up of more than two atoms. Examples of this use of single bonds include:

• Both bonds in HO
• All 4 bonds in CH

Single bonding even appears in molecules as complex as hydrocarbons larger than methane. The type of covalent bonding in hydrocarbons is extremely important in the nomenclature of these molecules. Hydrocarbons containing only single bonds are referred to as alkanes (Moore, Stanitski, and Jurs 334). The names of specific molecules which belong to this group end with the suffix –ane' Examples include ethane, 2-methylbutane, and cyclopentane (Moore, Stanitski, and Jurs 335).