Chemical Bonds, Lewis Symbols and Octet Rule

These flashcards cover key concepts related to chemical bonds, including the types of bonds, lattice energy, octet rule, polar and non-polar bonds, electronegativity, resonance structures, and formal charge calculations.

What are the three basic types of bonds in chemistry?

Ionic, Covalent, and Metallic.

What is ionic bonding?

Ionic bonding is formed by the transfer of one or more electrons from one atom to another.

What is the heat of formation of sodium chloride (NaCl)?

The heat of formation of sodium chloride is exothermic, with ΔH = -411 kJ/mol.

What is lattice energy?

Lattice energy is the energy required to completely separate a mole of a solid ionic compound into its gaseous ions.

How is lattice energy affected by ionic charge and size?

Lattice energy increases as the charges on the ions increase and with decreasing size of the ions.

What is the octet rule?

The octet rule states that atoms tend to react by gaining, losing, or sharing electrons to achieve eight valence electrons.

What is the difference between polar covalent bonds and non-polar bonds?

Polar covalent bonds occur when electrons are shared unequally between atoms, while non-polar bonds occur when electrons are shared equally.

What does electronegativity (EN) measure?

Electronegativity measures the ability of an atom in a molecule to attract electrons to itself.

What indicates a polar molecule in terms of electronegativity difference?

A polar molecule generally has an electronegativity difference (ΔEN) between 0.5 and 2.0.

What are resonance structures?

Resonance structures are equivalent Lewis structures of the same molecule that differ only in the placement of electrons.

How do you calculate formal charge?

Formal charge is calculated by: FC = number of valence electrons in free atom - (number of lone pair electrons + ½ number of bonding electrons).