Show your students a diagram illustrating the inside of a volcano. Point out the different parts, such as the reservoir, conduit, vent and sill, and explain the function of each. Talk about how the actual mountain or cone part of the volcano is formed by successive layers of lava and ash. To test what they’ve learned, ask them to draw their own similar diagramming, labeling the parts appropriately.
Not all lava is the same. Some runs out quickly, spreading a large distance and forming a volcano with shallow sides, called a shield volcano. Some oozes out very slowly. It doesn’t get very far before it cools and forms a volcano with steep, high sides called a composite volcano. Check the out Volcano Photo Gallery with your fifth graders. Comment on the different shapes of the volcanoes pictures and the ways that the lava looks and acts.
Find a map showing where the major volcanoes in the world are located. Discuss the following facts from the National Geographic and the website Science Kids: there about 15,000 active volcanoes on earth now, on both land and water. Many more are inactive. Three quarters of those make up the “ring of fire” along the Pacific Rim. There are volcanoes under the ocean and under ice caps. There are even volcanoes on other planets. Mars has a volcano called Olympic Mons that is 373 miles wide and 13 miles high. The place with the most continuously erupting volcanoes is Io, a moon of Jupiter.
Make a demonstration volcano with a washtub full of dirt and a jar. Press the dirt up around the jar to give it the appearance of a volcano. Into the jar add a 1/2 cup of water, a 1/2 cup of baking soda, 6 tbs. of dish soup and red food coloring. Stir thoroughly to create your lava. Into this mixture pour a 1/2 cup of vinegar. The vinegar will react with the soda, but slowly, so wait patiently to give the chemical reaction time to set it. Gradually, your lava will rise to the mouth of the volcano and flow over.