Ben and Sam were conducting experiments on physical and chemical changes in science class. First they added some salt to water and stirred it up until the salt dissolved. "That's a physical change" Ben said. "And that's a solution which is a mixture", added Sam. Next they added an anti-acid tablet to some water. The water began to fizz and bubble. The beaker got cooler. "That's a physical change too," Ben noted. "No, it's not," responded Sam. Who is correct and where should the contents of the beaker be placed in the Venn diagram?

Sam is correct. The reaction between the anti-acid tablet and water is a chemical change, not a physical change. The contents of the beaker should be placed in the "Chemical Change" circle of the Venn diagram.