Namse: Section \#: Date: Pre-lab 1. A student observes the following. Did a physical or chemical change occur for each set of observations? 2. A student uses filtration to separate a solid and a liquid. Did a physical or chemical change oceur? 3. A student separates a 7.52g mixture of iron, sand and sodium chloride salt using the procedure outlined in part A of this lab. Given the following data, calculate the percentage of each component in the mixture