Imagine you are making sandwiches. For each sandwich you need 2 pieces of bread, 3 slices of ham, 2 slices of turkey, and one slice of tomato. You have 21 pieces of bread, 18 pieces of ham, 20 pieces of turkey, and 15 slices of tomato. Which is the limiting reactant? Which reactant will you have in excess and how many of each will be left? Explain your answer and include definitions of a limiting reactant and an excess reactant.