Predict molecular shape

Answer Key - Grade 10 Science Worksheet - Challenge Me

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

1. 1.

   NH₃ has 3 H–N–H angles of 106.67° each. What is their total, to 0.01°, Ari?

   320.01 °
2. 2.

   BF₃ has 3 F–B–F angles of 120° each. What is their total, Bo?

   360 °
3. 3.

   CH₄ has 6 H–C–H angles of 109.47° each. What is their total, to 0.01°, Esme?

   656.82 °
4. 4.

   NH₃'s electron groups point to the corners of a tetrahedron. Why is its shape called pyramidal, Jun?

   • The lone pair is an atom
   • Nitrogen sits at one corner of the shape
   • Shape names only the atoms' positions
5. 5.

   NH₃'s three angles total about 320°. What does that show, Luz?

   • It is linear
   • It is a pyramid, not flat
   • It is flat and lies in one plane
6. 6.

   Milo says water must be linear because it has only two bonds. Agree or disagree?

   • Disagree: its lone pairs bend it
   • Agree: like CO₂
   • Agree: two bonds make a straight line
7. 7.

   Noah says NH₃ is flat like BF₃ because both have three bonds. Agree or disagree?

   • Disagree: NH₃ has a lone pair
   • Agree: three bonds lie flat
   • Agree: N and B are neighbors
8. 8.

   Pia says CO₂ is bent like water. Agree or disagree?

   • Agree: oxygen bends it
   • Agree: both have three atoms
   • Disagree: CO₂ has no lone pairs on C
9. 9.

   Which has the larger bond angle, BF₃ or CH₄, Ren?

   • CH₄, at 109.5°
   • BF₃, at 120°
   • They are equal
10. 10.

    Which molecule has the smallest bond angle of these five, Tala?

    • CO₂
    • H₂O
    • CH₄