Short lessons, printable activities, and conversation starters linked to the games already in the Corner. No student accounts are needed.
Open the free printable activity packet →Print from your browser or choose Save as PDF. The teacher answer key is separate below.
Lesson idea: Before opening the simulation, have students draw an element, a compound, and a mixture. Compare drawings with the particle models.
Discussion: Can a mixture contain both elements and compounds? Explain using a particle picture.
Lesson idea: Predict the shapes of CO₂, H₂O, and NH₃ before playing. Ask students to explain the role of lone pairs and bond-dipole cancellation.
Discussion: Why can a molecule have polar bonds but no net dipole in the ideal molecular model?
Lesson idea: Use the homepage’s weekly molecule and discovery as a quick discussion starter. Separate what the source reports from what students infer.
Discussion: Which claim can you support with a source, and which would need another experiment?
An element contains one kind of atom; a compound contains atoms of different elements chemically combined in fixed proportions. A mixture contains multiple substances. O₂ is an element, H₂O a compound, and O₂ + H₂O a mixture.
CO₂: linear, 180°, nonpolar overall in the ideal isolated-molecule model. H₂O: bent, about 104.5°, polar. NH₃: trigonal pyramidal, about 107°, polar. Lone pairs affect geometry; dipoles cancel in symmetric CO₂ but not in water or ammonia.
Answers vary. Look for a correctly named molecule, a formula checked against its record, a dated source link, and a distinction between observation and inference. Encourage questions; “we need more evidence” is a useful conclusion.
Original worksheets and lesson ideas: Dr. Masadeh’s Chemistry Corner. Linked simulations, records, and research remain credited to their creators. See Elements & Links for external resources.