7.1 The Covalent Bond

Covalent bond

Is a chemical bond that results from electron sharing.

Molecule

Is formed when two or more atoms bond covalently.

Lewis structure

Dots and lines are used to symbolize single covalent bonds.

Sigma bond

Single covalent bond

Chemical bond

The force that holds two atoms together

Why do atoms form bonds?

To gain stability by lowering energy

A bond formed by sharing electrons

Covalent bond

Two or more atoms bonded covalently

Molecule

Covalent bonds usually form between:

nonmetals

State some example of diatomic molecules:

H2, N2 ,F2 ,O2 ,I2 ,Br2 ,Cl2.

One shared pair of electrons is called:

Single bond

In Lewis structure, single covalent bond is shown by:

Dot or a line

Group 17 elements usually form how many covalent bonds?

One

Oxygen (Group 16) typically forms how many bonds?

Two

Give an example of a molecule with a triple bond:

N₂

True or False: Atoms with lower energy states are more stable.

True

True or False: A sigma bond is a of single covalent bond.

True

True or False: Double bonds involve three shared pairs of electrons.

False

True or False: Bond length increases as bond strength increases.

False

True or False: Exothermic reactions release more energy than the absorb.

True

How many covalent bonds does nitrogen usually form, and why?

Nitrogen forms three covalent bonds because it has five valence electrons and needs three more to be stable.

What happens to bond strength when bond length increases?

As bond length increases bond strength decreases.

Explain the difference between endothermic and exothermic.

• Endothermic absorbs energy; exothermic releases energy.

Why do diatomic molecules exist?

Because the two atom molecules are more stable than the individual atoms.

The most stable arrangement of atoms exists at

At the point of maximum net attraction, where atoms bond covalently to form a molecule.

The strength of an atom depends on:

The distance between two nuclei (bond length).