While cooking dinner for her family, Kate cut up some vegetables. She put the vegetables and water in the pot to make a soup and brought it to a boil. She threw away the potatoes that turned brown from oxidation. She turned the fire on the stove down so the soup could simmer. Thirty minutes later, she realized that there was less soup in the pot. She figured that some of the water in the soup must have evaporated. After she ate, she crumpled up her napkin, cleared the table and went to her room to study.