covalent bonding

• What type of bond is primarily discussed in this unit?

  Covalent bonds
• What do two chlorine atoms do to achieve a stable electron configuration?

  They share electrons
• What is the chemical formula for a chlorine molecule?

  Cl2
• What do the dots and crosses represent in a dot and cross diagram?

  Dots are from one atom, crosses from another
• What is the chemical formula for ammonia?

  NH3
• How many hydrogen atoms are in an ammonia molecule?

  Three hydrogen atoms
• What is the chemical formula for methane?

  CH4
• What is the shape of a methane molecule?

  Tetrahedron
• What type of bond is formed when two atoms share four electrons?

  Double bond
• What is the chemical formula for carbon dioxide?

  CO2
• What is a dative covalent bond?

  Electrons come from the same atom
• What is the ammonium ion formula?

  NH4+
• What affects the strength of covalent bonds?

  Bond length and bond type
• How does bond length affect covalent bond strength?

  Shorter bond lengths result in stronger bonds
• What is the relationship between single, double, and triple bonds?

  Triple bonds are stronger than double bonds
• What is the electronegativity trend across a period?

  Electronegativity increases across a period
• What happens to electronegativity as you go down a group?

  Electronegativity decreases down a group
• Which element has the highest electronegativity?

  Fluorine
• What is a polar molecule?

  A molecule with a positive and negative end
• What determines whether a bond is covalent or ionic?

  The difference in electronegativity between atoms
• What is the electronegativity difference range for a polar molecule?

  0.4 to 2
• What happens if the electronegativity difference is greater than 2?

  An ionic bond is formed
• What is the electronegativity of oxygen compared to hydrogen in water?

  Oxygen is more electronegative than hydrogen
• What is the chemical formula for water?


  H2O
• What are the key characteristics of covalent bonds?

  • Formed by sharing electrons
  • Can be single, double, or triple bonds
  • Strength depends on bond length
  • Dative covalent bonds involve shared electrons from one atom
• What are the trends in electronegativity across periods and down groups?

  • Increases across a period
  • Decreases down a group
  • Higher proton count increases electronegativity
  • More electron shells decrease electronegativity
• What types of bonds are formed based on electronegativity differences?

  • Pure covalent bond: no difference
  • Polar covalent bond: difference between 0.4 and 2
  • Ionic bond: difference greater than 2
• What is the significance of polar molecules like water?

  • Have a positive and negative end
  • Important for biological processes
  • Influence solubility and chemical reactions