Find the age t of a sample, if the total mass of carbon in the sample is mc, the activity of the sample is a, the current ratio of the mass of 14 6c to the total mass of carbon in the atmosphere is r, and the decay constant of 14 6c is ? . assume that, at any time, 14 6c is a negligible fraction of the total mass of carbon and that the measured activity of the sample is purely due to 14 6c. also assume that the ratio of mass of 14 6c to total carbon mass in the atmosphere (the source of the carbon in the sample is the same at present and on the day when the number of 14 6c atoms in the sample was set. express your answer in terms of the mass ma of a 14 6c atom, mc, a, r, and ? .

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?

For each of the following compounds, write the formula then predict whether it would be a strong, weak, or non-electrolyte when placed in di water. for the ionic compounds only, put (s) or (aq) after the forrmula formula strong, weak or non electrolyte? a calcium hydroxide b. silver carbonate c. lead(ii) sulfate d. phosphorus trifluoride e. sodium phosphide f barium sulfate g. strontium acetate h. zinc nitrate

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.