107Stories About ChemistryINDEX |
20.
A Bit of Linguistics, or Two Very Different Things
Without words there can be no speech, without letters, no words. We begin to study a language by learning the alphabet. Each alphabet contains two kinds of letters, vowels and consonants. Without either of these human speech would just go to pieces. There is a scientific fiction novel in which the inhabitants of an unknown planet speak to each other by means of sounds consisting only of consonants. But that is pure science fiction! Nature speaks to us in the language of chemical compounds. And each of these is a sort of combination of chemical �letters,� or elements occurring on Earth. The number of such �words� exceeds three million. But there are only just over a hundred �letters� in the chemical �alphabet.� This �alphabet� also contains �vowels� and �consonants.� The chemical elements have for ages been divided into two groups: nonmetals and metals. Nonmetals are much less numerous than metals. The ratio between them resembles a basketball score - 21 : 83. - also quite like in human speech, which has much fewer vowel than consonant sounds. A combination of only vowel sounds inhuman speech rarely expresses anything articulate. It is most often something like a senseless howl. In the chemical language combinations of only �vowels� (nonmetals) are rather common. All life on Earth owes its existence to compounds of the nonmetals with each other. Not in vain do scientists call the four main nonmetals - carbon, nitrogen, oxygen, and hydrogen - organogens, meaning substances which give rise to organic life. If we add phosphorus and sulphur, these six �bricks� just about exhaust the list of materials used by nature to build proteins and hydrocarbons, fats and vitamins - in a word, all vital chemical compounds. Two nonmetals, namely, oxygen and silicon (two �vowels� of the chemical �alphabet�) combine to form a substance written SiO2 and read silicon dioxide in the language of chemistry. This substance is the ultimate foundation of the Earth�s firmament, a kind of cement which keeps all the rocks and minerals from falling apart. It doesn�t take much more to complete the list of �vowels� of the chemical �alphabet�. All we have to add are the halogens, the rare gases of the zero group (helium, and its brothers) and three not very well known elements, boron, selenium and tellurium. However, it would be wrong to say that all living things On Earth are made up only of non�metals. Scientists have detected more than seventy different chemical elements in the human organism: all the nonmetals and a great number of metals, from iron to the radioactive elements, including uranium. The reason why there are more consonants than vowels in the human language has long been a point of controversy among linguists. Chemists are interested in why there are two such different groups as nonmetals and metals in the Periodic System. Each of these groups includes elements which differ greatly from one another, but there is nevertheless some resemblance between them. |