One night Lorna placed a big slice of sweet watermelon in the freezer to cool it with the intention of serving it at the breakfast table the following day. The next morning, she found the fruit too hard to slice. She had to thaw it. To her dismay, she found the fleshy part of the fruit too soft. It has lost the crisp bite she expected from the fresh fruit. What happened? Was the change in the watermelon physical or chemical? Explain your answer.​