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General Chemistry

Single Bond

Definition and meaning of Single Bond in chemistry.

A single bond is a chemical link between two atoms that share one pair of electrons. It is the most common type of connection found throughout chemistry. This bond forms the basic skeleton of almost all molecular structures.

In more detail

To make a single bond, two atoms each bring one valence electron to share. They hold these two outer electrons in a shared space directly between their nuclei. This shared region is known as a sigma bond.

The negative charge of the electrons attracts the positive nuclei of both atoms. This mutual attraction holds the two atoms firmly together. Single bonds are very stable under normal conditions.

They also allow the bonded atoms to spin freely. You can picture this like two solid spheres connected by a straight metal rod. The spheres can twist around on the rod without breaking the connection.

This free rotation makes many large molecules highly flexible. It allows them to bend and fold into complex three-dimensional shapes. A common student mistake is thinking a single bond is inherently weak.

While a single bond is weaker than a double bond, it is still a very strong force. It requires a significant amount of heat or energy to break it apart completely. You will see single bonds in almost every type of organic molecule.

They connect carbon atoms in long continuous chains to make fuels. They also form the backbone of everyday plastics and living tissues. Chemists always draw a single bond as a single straight line.

When you see a plain line between two letters in a diagram, it represents exactly two shared electrons.

Key facts

Bond representationSingle straight line between atoms
Electrons sharedOne pair (exactly 2 electrons)
Rotational freedomAllows free rotation around the bond
Bond strengthWeaker than double or triple bonds
FieldGeneral Chemistry
Example

In a molecule of water (H2O), two separate single bonds connect the central oxygen atom to each hydrogen atom. The oxygen atom shares one electron with the first hydrogen atom. It shares another electron with the second hydrogen atom. This gives all three atoms a stable electron arrangement.

Frequently asked questions

How is a single bond different from a double bond?

A double bond shares four electrons and prevents free rotation. A single bond shares two electrons and lets the atoms spin freely.

What happens to the electrons in a single bond?

The two shared electrons spend most of their time in the space directly between the two atomic nuclei.

Can a single bond bend or stretch?

Yes, atoms vibrate constantly at room temperature. A single bond acts like a stiff spring that can stretch and bend slightly.

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