Ionic

• What type of structure does silicon have?


  Macromolecular structure
• How are ionic compounds formed?


  Through the transfer of electrons from metal atoms to non-metal atoms
• What happens to metal atoms during ionic bonding?


  They lose electrons from their outer energy levels
• What happens to non-metal atoms during ionic bonding?


  They gain electrons to fill their outer energy levels
• What is the result of atoms losing and gaining electrons?


  They become ions with an overall charge
• What are positive ions called?

  Cations
• What are negative ions called?

  Anions
• How can the formation of ions be represented?


  Using electron configurations
• What is an ionic bond?


  The electrostatic attraction between oppositely charged ions
• How do sodium and chlorine atoms react to form ions?


  Sodium loses its 3s¹ electron, and chlorine gains one electron
• What is the electron configuration of a sodium ion?


  1s² 2s² 2p⁶
• What is the electron configuration of a chloride ion?


  1s² 2s² 2p⁶ 3s² 3p⁶
• What is the formula of an ion of element X with 2 electrons in its outer shell?


  X²⁺
• What is the formula of an ion of element Y with 7 electrons in its outer shell?


  Y^-
• What is the formula of the compound formed between elements X and Y?


  XY₂
• What is the structure of ionic solids?


  • Ions held in a three-dimensional framework called an ionic lattice
  • Regular repeated arrangement of ions
  • Example: NaCl lattice has each Na⁺ surrounded by 6 Cl^- ions
• What causes the crystalline nature of ionic compounds?


  The regular pattern of ions within the structure
• What happens to sodium chloride when heated?


  It makes a cracking sound due to the ionic crystalline structure breaking up
• What is the melting point of sodium chloride?


  797°C
• Why do ionic compounds have high melting points?


  Due to the large number of strong electrostatic attractions between ions
• How does the size and charge of ions affect ionic bond strength?


  Smaller ions and higher charges result in stronger ionic bonds
• What is the melting point of magnesium oxide?


  2852°C
• Why are positive ions generally smaller than the atoms from which they are formed?


  They lose electrons, resulting in a smaller electron cloud
• Why are negative ions larger than the parent atom?


  Repulsion between electrons moves them further apart
• What is the melting point trend among sodium chloride, sodium bromide, and sodium iodide?


  The melting point decreases from sodium chloride to sodium iodide
• Why is potassium chloride soluble in water?


  Water surrounds the ions that break out of the lattice
• What are two properties of potassium chloride typical of ionic compounds?


  High melting point and electrical conductivity when molten
• What is the charge on a sodium ion?


  +1
• What is the formula for the ammonium ion?


  NH₄⁺
• What is the formula for the sulfate ion?


  SO₄²⁻
• What is the formula for the nitrate ion?


  NO₃⁻
• What is the formula for the hydroxide ion?


  OH⁻
• What is the formula for the carbonate ion?


  CO₃²⁻
• What is the formula for the hydrogen carbonate ion?


  HCO₃⁻
• What are the properties of ionic compounds?


  • High melting and boiling points
  • Usually solid at room temperature
  • Soluble in water
  • Conduct electricity when molten or in aqueous solution
• What is the significance of ionic compounds containing molecular ions?


  They exhibit the properties of ionic compounds despite containing covalent bonds within the ions
• How should you work from a formula to a name or from a name to a formula for ionic compounds?


  By identifying the ions present and their charges
• What is the formula for sodium carbonate?


  Na₂CO₃
• What is the formula for ammonium sulfate?


  (NH₄)₂SO₄