Heart palpitations are described as feeling like your heart is racing or pounding. Palpitations can be caused by anxiety, panic disorders, overeating, pregnancy, and abnormal heart rhythms (arrhythmias). Most palpitations are not serious, however, palpitations caused by a heart condition like atrial fibrillation or Afib can be serious and require medical treatment.
WEIGHING BY DIFFERENCE (From Dr. David Chesney) Weighing by difference is the most accurate method to measure quantitatively the mass of a solid sample. This procedure involves repetitive weighings of a weighing bottle containing a quantity of solid reagent. As the solid is removed to another vessel, the mass of the weighing bottle contents decreases.
Weight is different from mass. Weight is the measure of the force of gravity on an object. The mass of an object will never change, but the weight of an item can change based on its location. For example, you may weigh 100 pounds on Earth, but in outer space you would be weightless. However, you will always have the same mass on Earth as you have in outer space.