Why is the mass of an iron atom different from the mass of a copper atom?

Iknow the answer is a but i don't know why

Actual ingredients of lab (the cookies i am actually making) 1/2 cup sugar 1/2 cup brown sugar 1 1/3 stick margarine 1 egg 1/2 tsp salt 1 tsp vanilla 1/2 tsp baking soda 1 1/2 cup flour 1 1/3 cup chocolate chip can you answer the questions below ? discussion 1. suppose you are given the following amounts of ingredients: 1 dozen eggs 24 tsp. of vanilla 1 lb. (82 tsp.) of salt 1 lb. (84 tsp.) of baking soda 3 cups of chocolate chips 5 lb. (11 cups) of sugar 2 lb. (4 cups) of brown sugar 1 lb. (4 sticks) of margarine a. for each ingredient, calculate how many cookies could be prepared if all of that ingredient were consumed. (for example, the recipe shows that using 1 egg- with the right amounts of the other ingredients- yields 24 cookies. how many cookies can you make if the recipe is increased proportionately for 12 eggs? ) b. to determine the limiting reactant for the new ingredients list, identify which ingredient will result in the fewest number of cookies. c. what is the maximum number of cookies that can be produced from the new amounts of ingredients?

Electrons are extremely important to what area of technology? a) anti-aging research b) household product development c) electronics d) drug discovery