Chemical Bonds

Chemical Bonds

Key Concepts

  • Chemical Bond Formation

    • Atoms may gain, lose, or share electrons when forming a chemical bond.

    • Possible particles:

      • (1) Protons

      • (2) Electrons

      • (3) Neutrons

      • (4) Nucleons

Stability During Bond Formation

  • The stability of a chemical system generally increases during bond formation.

    • (1) Decreases

    • (2) Increases

Energy in Chemical Bonds

  • The kind of energy stored in a chemical bond is known as potential energy.

    • (1) Potential energy

    • (2) Kinetic energy

    • (3) Activation energy

    • (4) Ionization energy

Valence Electron Configuration

  • The configuration of eight valence electrons is known as an octet.

    • (1) An octet

    • (2) A cation

    • (3) An anion

    • (4) An ion

Changes in Potential Energy

  • When a chemical bond forms between two hydrogen atoms, the potential energy of the atoms decreases.

    • (1) Decreases

    • (2) Increases

Argon and Stability

  • An atom of argon rarely bonds with an atom of another element because it has 8 valence electrons, indicating it has a stable electron configuration.

    • (1) 8 valence electrons

    • (2) 2 electrons in the first shell

    • (3) 3 electron shells

    • (4) 22 neutrons

Barium Atom and Stability

  • A barium atom attains a stable electron configuration when it combines with two chlorine atoms.

    • (1) One chlorine atom

    • (2) Two chlorine atoms

    • (3) One sodium atom

    • (4) Two sodium atoms

Covalent Bond Formation

  • Covalent bonds are formed when electrons are shared between two atoms.

    • (1) Transferred from one atom to another

    • (2) Captured by the nucleus

    • (3) Mobile within a metal

    • (4) Shared between two atoms

Electron Sharing and Bond Type

  • As a bond between a hydrogen atom and a sulfur atom is formed, electrons are shared to form a covalent compound.

    • (1) Shared to form an ionic compound

    • (2) Shared to form a covalent compound

    • (3) Transferred to form an ionic compound

    • (4) Transferred to form a covalent compound

Identification of Covalent Compounds

  • The two substances that are covalent compounds are:

    • (2) C6H12O6(s) and HCl(g)

    • (1) C6H12O6(s) and KI(s)

    • (3) KI(s) and NaCl(s)

    • (4) NaCl(s) and HCl(g)

Properties of Molecular Substances

  • A significant property of molecular substances is a low melting point.

    • (1) Good heat conductivity

    • (2) Good electrical conductivity

    • (3) Low melting point

    • (4) High melting point