Introduction:Accurate and precise weight measurements are crucial when performing laboratory experiments because the results are dependent on the data. When working in an analytical chemistry lab there are many things that measurements depend on. Measurements are the fundamental component of science and it is in the numbers where we can find the answer we are looking for. When determining the mass of a substance that is a chemical, small, or simply not able to place on the balance alone the ‘Difference method’ is used. When performing ‘The Difference Method’ the mass of the weighing paper or weighing bottle is determined and recorded first. Then, add the substance to the weighing paper or weighing bottle and record that weight. Lastly, subtract the mass of the weighing paper from the total measurement to determine the accurate weight of the substance. While calibrating glassware you are also familiarizing yourself with different tools within the laboratory. This will help to perform each experiment with accuracy. Human error or misuse of the instruments within the laboratory can often be consequence of false results. Clean instruments also play a huge role in experiments. Even with gloves on, our hands can pick up all kinds of germs, oil, and debris. We must assume that all glassware is dirty as well, so before beginning an experiment glassware must be washed and dried to steer clear from anything that may alter the results. The analytical balance is very sensitive and leaving any of its doors open while weighing could alter the mass. It is important tobe introduced to the tips that alter experiments to prevent difficulty in the lab. The work of an analytical chemist is very important and therefore must be very precise. The results could result in life and death but for now the weight of a penny and calibrating the glassware is where it will begin. Materials: Weigh paperPenny Analytical Balance 10 mL pipetteBuretteDeionized waterKim wipesTweezers 50 mL volumetric flask Beakers Procedure:Weighing a CoinPart 11.)Turn on analytical balance and zero it out.