Chapter 1, Problem 1.20E

Consider the following experiments, and answer the questions pertaining to classification:

a. A pure substance R is heated, cooled, put under pressure, and exposed to light but does not change into anything else. What can be said about classifying substance R as an element or a compound? Explain your reasoning.

b. Upon heating, solid pure substance T gives off a gas and leaves another solid behind. What can be said about classifying substance T as an element or compound? Explain your reasoning

c. What can be said about classifying the solid left in part b as an element or compound? Explain your reasoning.