Crnogorski
Unit of the month: MOLE
602 214 076 000 000 000 000 000, or approximately 602 trillion, has 24 digits. As unimaginably large as this number may seem to us, we encounter trillions of things constantly in everyday life! In a standard balloon, for example, there are about 50 trillion air molecules (that means about 39 trillion nitrogen molecules, 10 trillion oxygen molecules and half a trillion argon atoms). A standard painkiller contains around 1.7 trillion molecules of the active ingredient – for example acetylsalicylic acid. One litre of mineral water contains about 1 trillion sodium atoms. As you can see, large quantities appear when we look at extremely small things, such as atoms and molecules. In physics and chemistry, atoms and molecules are very often dealt with, but scientists don’t always want to juggle with such large numbers. This is why large particle numbers are combined into a kind of “imaginary count bundle” and this bundle is the unit of the month for April: the mole, the unit of an amount of substance.
By using the mole, particle numbers can be expressed in a much more manageable way. Instead of “in a balloon there are about 10 trillion oxygen molecules” we can say, “in a balloon there are about 0.02 mole of oxygen”. The conversion factor between the number of particles and the amount of substance (and in a way and our special count bundle) is the so-called Avogadro constant NA. This states that one mole contains 602 214 076 000 000 000 000 000 particles. Needless to say, we usually don’t care about the number of oxygen atoms in a balloon. However, in medicines or food, and many other areas of life, it is important to know how much there is of something. In pharmacy and analytical chemistry, for example, the amount of substance and the so-called molar quantities are used all the time, because it is easier to calculate with sizes such as “0.01 mol per litre” instead of “6 022 140 760 000 000 000 particles per litre”.
