Achemist who studies water samples did a demonstration of how to test for lead in water. she added a clear solution of potassium iodide to a clear solution of lead nitrate. then a yellow swirling solid formed in the liquid. what is most likely true about the yellow solid? a. it is a new substance with different properties. b. it is solid lead nitrate. c. it is solid potassium iodide. d. it was secretly added to the test tube by the scientist.