Draw a side view of a volcano during an eruption. Include the crater. Show the lava, gas and ash released during the eruption. Draw the vent and the magma chamber, deep below the Earth's surface. Write a list of the terms on the right side of the board. Ask students to copy both the volcano design and the terms' list on their notebooks. Start explaining how a volcano "works" using the terms you have written; for example, say, "A volcano begins with a crack, called vent. This vent extends up to 40 miles inside the Earth." Students must listen carefully to what you say and name each part of the volcano, using the words from the list.
Point at the magma chamber on the design you have created on the board. Explain that deep below the Earth's surface, the conditions are so hot that some rocks melt and create the so-called magma. Move your focus to the vent, telling students that magma is lighter than solid rock and rises toward the surface by pushing through vents. Draw arrows on the design to help students understand the process better. When the magma eventually reaches the surface, the volcano erupts. At this point, show pictures of volcano eruptions to students and point toward the lava, gas and ash released.
Volcanoes come in three main shapes. These are the "stratovolcanoes" -- or "composite volcanoes" -- which form a symmetrical cone with steep sides; "cinder cones," which are small conical volcanoes, and "shield volcanoes" which resemble a soldier's shield. Draw all three types of volcanoes on one side of the board and write down their names -- in random order -- on the other side. Describe each volcano type's shape in simple words and ask students to match each drawing with its corresponding term.
Bring a small soda bottle and a large ball to the classroom. Place the bottle in the middle of the bowl and ask students to use clay to build a mountain around the ball, so that it resembles a real-life volcano. Remove the lid and fill half the bottle with warm water. Use food coloring to make the water red. Put six drops of liquid detergent and 3 tbsp. baking soda in the bottle and pour vinegar slowly and carefully into the bottle. The volcano will erupt, releasing smoke and a red foamy fixture, resembling the lava.