Effusive eruptions release flowing lava; explosive eruptions fragment material and eject it. Viscosity means resistance to flow. Gas content, how easily gas escapes, and other conditions affect behaviour. Broad shields often grow from fluid flows. Composite cones combine different deposits. Shape alone does not tell us what the next eruption will do. Safety: Paper diagram only. Do not reproduce an explosive eruption or use an actual volcanic site. Stop: Stop after the comparison. No syrups, powders, pressure, reacting mixtures, or heated materials.

Materials: Paper; Pencil; Ruler 1. Draw two profiles on matching 12 cm baselines: A rises 2 cm above its middle; B rises 5 cm. Label them Illustrative profiles, not real measurements. A is a broad shield example; B is a steeper composite-cone example. 2. Copy four cards: 1 Low-viscosity lava flows outward in repeated thin deposits. 2 Gas becomes trapped in viscous magma and material fragments during escape. 3 A cone builds from alternating lava and fragmented deposits. 4 A shield volcano can also have explosive activity. Place cards beside the profile they explain or qualify. 3. Add arrows and labels for flow on A and ejected fragments above B. Write a comparison using viscosity and gas escape. Replace the word safe with effusive if it appears: a lava flow can still be dangerous. 4. Write a caution under both profiles: Eruption styles can change. Explain why a tall outline is not enough to forecast an eruption; scientists need monitoring and eruption history too. Done: Two labelled profiles, four placed cards, a flow-versus-fragment comparison, and one forecasting caution are complete. Proof: Keep the profiles and comparison. Note help with dimensions, vocabulary, or card placement. No physical eruption experiment occurred. Stop: Stop after the comparison. No syrups, powders, pressure, reacting mixtures, or heated materials.