Covalent Bonds and Molecular Compounds Review

Covalent bond

A bond formed by sharing electrons between atoms.

Molecule

A group of atoms held together by covalent bonds.

Bond length

The optimum distance between nuclei in a covalent bond where net attractive forces are maximized and the molecule is most stable.

Diatomic molecule

Molecules made up of 2 of the same atom, whose formation increases stability due to overlap of orbitals.

Seven diatomic elements

Nitrogen (N2), oxygen (O2), hydrogen (H2), fluorine (F2), chlorine (Cl2), bromine (Br2), and iodine (I2).

Octet rule

The principle that compounds share enough electrons to complete eight valence electrons (s and p filled) around each atom.

Molecular compounds

Compounds that consist of molecules rather than ions, typically formed by nonmetals sharing valence electrons.

Multiple covalent bonds

Covalent bonds formed by sharing more than two electrons between atoms when single bonds are insufficient to satisfy the octet rule.

Single bond

A covalent bond formed by sharing one electron pair, represented by a single line (e.g., H-H).

Double bond

A covalent bond formed by sharing two electron pairs, represented by a double line (e.g., O=O).

Triple bond

A covalent bond formed by sharing three electron pairs, represented by a triple line (e.g., N≡N).

Coordinate Covalent Bond

A covalent bond that forms when both shared electrons are donated by the same atom.

Polyatomic Ion

An ion where the number of protons and electrons are not equal, but the bonds between its constituent atoms are covalent.

Ionic Compounds (characteristics)

Composed of ions (metals with nonmetals), crystalline solids, high melting/boiling points, conduct electricity when molten or dissolved, many are water-soluble.

Molecular Compounds (characteristics)

Composed of molecules (nonmetals with nonmetals), gases, liquids, or low-melting-point solids, low melting/boiling points, do not conduct electricity, many are soluble in organic liquids.

Intermolecular forces

Forces that exist between molecules, which determine the physical