Draw Lewis structures of molecules

Grade 10 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

  1. Water has 8 valence electrons and 2 bonding pairs. How many lone pairs are in 3 water molecules, Ari?

  2. Carbon dioxide has 16 valence electrons and 4 bonding pairs. How many lone pairs are in 3 CO₂ molecules, Bo?

  3. Oxygen gas, O₂, has 12 valence electrons and 2 bonding pairs. How many lone pairs are in 5 O₂ molecules, Esme?

  4. A drawing gives carbon five bonds. What is wrong, Kira?

    • Carbon would have 10 electrons
    • Nothing is wrong
    • Carbon needs six bonds to be full
  5. A drawing of H₂O shows 10 electrons. What is wrong, Luz?

    • Oxygen needs 10
    • It needs 12 electrons for the oxygen
    • Water has only 8 valence electrons
  6. Milo says water's oxygen has only 4 electrons because it has two bonds. Agree or disagree?

    • Agree: just the bonding pairs count
    • Disagree: its lone pairs count too
    • Agree: two bonds is four
  7. Noah says nitrogen in NH₃ breaks the octet rule with only 3 bonds. Agree or disagree?

    • Disagree: its lone pair makes 8
    • Agree: nitrogen needs 5 bonds to be full
    • Agree: 3 bonds make 6
  8. Why does CO₂ need double bonds, Ren?

    • Single bonds leave carbon short
    • Carbon has too many electrons already
    • Oxygen is too small
  9. How is a double bond made when drawing a Lewis structure, Tala?

    • A lone pair becomes a shared pair
    • Electrons are removed
    • A new atom is added
  10. Why does H₂O need no double bonds, Zee?

    • Hydrogen forms two bonds
    • Oxygen has no lone pairs
    • Single bonds already complete it
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Draw Lewis structures of molecules

Answer Key - Grade 10 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

  1. Water has 8 valence electrons and 2 bonding pairs. How many lone pairs are in 3 water molecules, Ari?

    6 lone pairs
  2. Carbon dioxide has 16 valence electrons and 4 bonding pairs. How many lone pairs are in 3 CO₂ molecules, Bo?

    12 lone pairs
  3. Oxygen gas, O₂, has 12 valence electrons and 2 bonding pairs. How many lone pairs are in 5 O₂ molecules, Esme?

    20 lone pairs
  4. A drawing gives carbon five bonds. What is wrong, Kira?

    • Carbon would have 10 electrons
    • Nothing is wrong
    • Carbon needs six bonds to be full
  5. A drawing of H₂O shows 10 electrons. What is wrong, Luz?

    • Oxygen needs 10
    • It needs 12 electrons for the oxygen
    • Water has only 8 valence electrons
  6. Milo says water's oxygen has only 4 electrons because it has two bonds. Agree or disagree?

    • Agree: just the bonding pairs count
    • Disagree: its lone pairs count too
    • Agree: two bonds is four
  7. Noah says nitrogen in NH₃ breaks the octet rule with only 3 bonds. Agree or disagree?

    • Disagree: its lone pair makes 8
    • Agree: nitrogen needs 5 bonds to be full
    • Agree: 3 bonds make 6
  8. Why does CO₂ need double bonds, Ren?

    • Single bonds leave carbon short
    • Carbon has too many electrons already
    • Oxygen is too small
  9. How is a double bond made when drawing a Lewis structure, Tala?

    • A lone pair becomes a shared pair
    • Electrons are removed
    • A new atom is added
  10. Why does H₂O need no double bonds, Zee?

    • Hydrogen forms two bonds
    • Oxygen has no lone pairs
    • Single bonds already complete it