Bonding Review – Honors Chemistry

Bonding Review – Honors Chemistry

• Why do atoms bond? Atoms bond to achieve a more stable electron configuration, usually by filling their outermost electron shell (octet rule).

• Octet Rule: Atoms tend to gain, lose, or share electrons to achieve a full outer electron shell of eight valence electrons (except for hydrogen and helium, which are stable with two).

Ionic Bonds

• Definition: Ionic bonds form when one or more electrons are transferred from a metal atom to a nonmetal atom. This creates oppositely charged ions that are attracted to each other due to electrostatic forces.

• Example: Sodium chloride (NaCl). Sodium loses one electron to become Na⁺, and chlorine gains one electron to become Cl⁻. These oppositely charged ions attract, forming an ionic bond.

Covalent Bonds

• Definition: Covalent bonds form when atoms share one or more pairs of electrons. This sharing allows both atoms to achieve a more stable electron configuration resembling a full outer shell.

• Example: Water (H₂O). Hydrogen and oxygen share electrons to complete their respective outer electron shells.

Ionic Compound Formulas

• Na and O: Na₂O
• Al and Cl: AlCl₃
• Fe²⁺ and N³⁻: Fe₃N₂

Lewis Structure - Ca and Br

• Formula: CaBr₂
• Lewis Structure: A Lewis structure showing Ca transferring two electrons to two Br atoms, forming Ca²⁺ and two Br⁻ ions.

Compound Names

• N₂O: Dinitrogen monoxide
• SnS₂: Tin(IV) sulfide
• Ba(ClO₂)₂: Barium chlorite
• FeSO₄: Iron(II) sulfate
• PCl₅: Phosphorus pentachloride
• Ca₃(PO₄)₂: Calcium phosphate
• BeC₂O₄: Beryllium oxalate
• CF₄: Carbon tetrafluoride

Compound Formulas

• Sulfur hexafluoride: SF₆
• Copper(II) nitrate: Cu(NO₃)₂
• Cesium oxide: Cs₂O
• Ammonium phosphite: (NH₄)₃PO₃
• Lead(IV) chloride: PbCl₄
• Diphosphorous pentoxide: P₂O₅
• Aluminum sulfite: Al₂(SO₃)₃
• Nitrogen monoxide: NO

Ionic Compounds – Structure and Properties

• Structure: Arranged in a crystal lattice structure with alternating positive and negative ions.
• Properties: Typically hard, brittle, high melting/boiling points, dissolve in water to form conducting solutions.
• Examples: Sodium chloride (NaCl), potassium iodide (KI), magnesium oxide (MgO).

Covalent Compounds – Structure and Properties

• Structure: Atoms are bonded to form molecules; molecules are held together by weaker intermolecular forces.
• Properties: Generally lower melting/boiling points than ionic compounds, many are gases or liquids at room temperature, many are not soluble in water.
• Examples: Water (H₂O), methane (CH₄), carbon dioxide (CO₂).

Identifying Ionic vs. Covalent

• Test: Melt the compound and check if it conducts electricity.
  • If it conducts when melted, it is ionic.
  • If it does not conduct when melted, it's likely covalent.

Lewis Structures (Question 11)

• Lewis Structures are visual representations of how valence electrons are shared or transferred in a bond. For each requested molecule, the Lewis structure diagrams the bonding, as well as the lone pairs of electrons. This structural information was not explicitly supplied and students should use the formulas and rules to draw correct structures.

Bond Types (Question 14)

• Polar: Unequal sharing of electrons between atoms, creating a dipole moment.
• Nonpolar: Equal sharing of electrons, no dipole moment.
• Ionic: complete transfer of electrons, creating charged ions.

Metallic Bonds

• Definition: Metallic bonds involve the sharing of many delocalized electrons in a metal. The electrons are free to move between atoms, resulting in a strong attraction between positive metal ions and the surrounding "sea" of electrons.

Covalent Network Bonds

• Description: Covalent network bonds form an extensive network of strongly bonded atoms. These networks are effectively giant molecules.
• Example: Diamond (carbon)
• Properties: Covalent network substances are typically very hard, have high melting points, and poor electrical conductivity.

Explore the fundamentals of atomic bonding in this quiz, focusing on why atoms bond, the octet rule, and the distinctions between ionic and covalent bonds. Test your understanding of electron transfer and sharing, key concepts in chemistry.