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Home  / GENERAL CHEMISTRY Textbook / Chapter 3. General Chemistry

Chapter 3. General Chemistry

Bearing in mind that, after all, the whole world and we, ourselves, are all made up of substances, here are the main questions concerning substances, that are answered by general chemistry:  

1. What is the smallest particle of a substance?

2. At the expense of what forces do these particles bond with each other?

3. How do the bonds between the particles break up in the course of transformation?

4. How is the likeness and difference of substances that surround us defined?

The world-famous bongo drums player, Richard Feynman, who won the Nobel Prize for Physics, asked: "What is the shortest phrase, concerning the most important scientific knowledge we possess, would you pass on to the next generation?" Feynman, himself answered: "Everything is made of atoms."

Then he went on to say: "But what is their size and shape?" the next generation might ask, "and how do they stick together?" [Colin J.Humphrey, NATURE, September 1999 #401 p.21.]

It is a known fact that all the substances around us (iron, stone, salt, bread, liquids, etc.) consist of molecules, which are the smallest particle of a substance consisting of atoms. An atom consists of a positively charged nucleus around which negatively charged electrons rotate. A nucleus consists of nucleons (protons and neutrons).

Protons are always positively charged, their charges (in absolute units) being equal to those of the electrons.

Neutrons do not carry any electrical charges. Protons and neutrons consist of quarks.

There are 6.02 · 1023 molecules of water in 18 grams of water. A molecule of water consists of an atom of oxygen (O) and two atoms of hydrogen (H), i.e., H2O.

An oxygen atom consists of a nucleus and 6 electrons.

A hydrogen atom consists of a nucleus and one electron.

To break up water into molecules, we must heat the water to a temperature of 100° C.  To further break up a water molecule into atoms, we must heat the steam of the water to a temperature of about 5,000° C. 

To tear away the electrons of the oxygen atom from its nucleus, it is necessary to raise the temperature to more than 10,000° C.

Thus, according to experimental data, the limit for breaking up particles into the smallest unit possible depends on the temperature (energy) that we use in order to break up the substance.

Now let's see how the atom is constructed.

* Atomic structure  >>