Page 69 - The Miracle in the Atom

hat is it that makes the objects you see in your surroundings
different from each other? What is it that discriminates their
colours, shapes, smells, and tastes? Why is one substance
W soft, another hard, and yet another fluid? From what you ha-
ve read so far, you may answer these questions saying, "The differences bet-
ween their atoms do this". Yet, this answer is not sufficient, because if the
atoms were the cause for these differences, then there would have to be billi-
ons of atoms bearing different properties from each other. In practice, this is
not so. Many materials look different and bear different properties although
they contain the same atoms. The reason for this is the different chemical
bonds the atoms form among them to become molecules.
On the way to matter, molecules are the second step after atoms. Mole-
cules are the smallest units determining the chemical properties of matter.
These small bodies are made up of two or more atoms and some, of tho-
usands of groups of atoms. Atoms are held together inside molecules by che-
mical bonds determined by the electromagnetic force of attraction, which
means that these bonds are formed on the basis of the electrical charges of
the atoms. The electrical charges of atoms, in turn, are determined by the
electrons on their outermost shell. The arrangement of molecules in different
combinations give rise to the diversity of matter we see around us. The im-
portance of the chemical bonds that lie at the heart of the diversity of matter
come forward at this very point.

Chemical Bonds
As explained above, chemical bonds are formed through the motion of
electrons in the outermost electron shells of the atoms. Each atom has a ten-
dency to fill up its outermost shell with the maximum number of electrons it
may shelter. The maximum number of electrons the atoms can hold in their
outermost shells is 8. To do this, atoms either receive electrons from other
atoms to complete the electrons in their outermost shells to eight, or if they
have lesser electrons in their outermost shells, then they give these to anot-
her atom, making a sub-shell that had previously been completed in their
outermost orbits. The tendency of the atoms to exchange electrons constitu-
tes the basic inciting force of the chemical bonds they form between each ot-
her.

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