Unit 1 Investigation, Models, and Measurement Essential Questions 1. What are the branches of earth science and what does each branch study or do? 2. What are the six steps of the scientific method, how does each step help solve a problem or find an answer, and why is it useful to scientist? 3. What is a model, how are they useful to scientists? 4. What is the metric system (SI), and what are the benefits of using it?