*What is the role of gases in providing energy for explosive volcanic eruptions? *How does pressure effect gases? *How do gases influence the texture and appearance of volcanic rock? Objective Students will examine how gases provide for explosive volcanic eruptions by making comparisons to gases in a soda bottle and by conducting a carefully controlled "eruption" of baking soda/vinegar or soda water. By the end of the lesson, students will be able to answer the questions: *What is the role of gases in providing energy for explosive volcanic eruptions? *How does pressure effect gases? *How do g Duration: 60 Minutes.