2010 On Line Technocracy Study Course project
Page 15
GO Bottom
Lesson 1
The earth and everything upon it is composed of matter. Matter occurs in three principle physical states--solids, liquids, and gases. Examples of solids are rocks, wood, ice. Examples of liquids are water, gasoline, alcohol. Examples of gases are air, illuminating gas, water vapor or steam.
Molecules.
The smallest particle of any pure
substance, such as water, Iron or salt, which can exist without that substance
changing it's physical properties is called a molecule.. Thus, water is
made up of millions of water molecules, each of which is, so far as we know,
exactly like every other water molecule. These water molecules are much too
small to be seen by even the most powerful microscope. There are ways of
measuring them quite accurately, however, as to weight and size.
Change of Physical State.
Matter can be changed from one physical
state to another. Thus, by the application of heat, water can be changed from
it’s solid state ice, to it's liquid state, water; and by further heating to
it's gaseous state, water vapor. In a similar manner air, which is normally
gaseous, by cooling and compression, can be converted into liquid air, and this
by still further cooling, can be frozen solid.
Elements.
There are compound substances and simple
substances, or elements. Common salt, a compound substance, for
instance, can be separated by electrical means into two substances--the metal
element Sodium; and the poisonous gas element, Chlorine. Water, in like manner,
can be resolved into two constituent gases, the elements Oxygen and Hydrogen.
Marble, similarly, can be divided into the elements Carbon, Calcium, and
Oxygen.
Page
16 GO
All of those last named substances are characterized by this fact, they cannot be further subdivided. They are called chemical elements. Chemical elements are the building materials of which everything else on earth is composed.
There are only 92 chemical elements. Several of these are relatively common in everyday life. Among the better known elements are Iron, Aluminum, Copper, Tin, Lead, Zinc, Silver, Gold, Platinum, Oxygen, Carbon, Sulphur, Hydrogen, Nitrogen, Chlorine, Iodine, and Nickel.
Some of the elements are exceedingly rare, and have been obtained only in extremely minute traces. Other elements are very common.
Estimates based upon the averaging of thousands of chemical analysis show the upper 10 miles of the earth's crust to be composed of the following elements in approximately the percentages given.
Table 1
Chemical Composition of the Outer
10 miles of the Earth:
Oxygen . . . . . . . . . . . . . . . . . 46.59
Silicon . . . . . . . . . . . . . . . . . 27.72
Aluminum . . . . . . . . . . . . . . . 8.13
Iron . . . . . . . . . . . . . . . . . . . . . 5.01
Calcium . . . . . . . . . . . . . . . . . 3.63
Sodium . . . . . . . . . . . . . . . . . . 2.85
Potassium . . . . . . . . . . . . . . . 2.28
Magnesium . . . . . . . . . . . . . . 2.09
Titanium . . . . . . . . . . . . . . . . . 0.63
Phosphorus . . . . . . . . . . . . . . 0.13
Hydrogen . . . . . . . . . . . . . . . . 0.13
Manganese . . . . . . . . . . . . . . . 0.10
--------
99.29
All remaining 80 elements . . 0.71
----------
Total, 92 elements . . . . . . . 100.00
The striking thing about this table is that by far the greater part of the materials comprising the surface of the earth is composed of only five or six chemical elements. Most of the familiar
Page
17 GO
metals that are used daily occur in amounts of less than one-tenth of one percent of the surface rocks of the earth.
Atoms.
The smallest particle of a chemical element
is called an atom. A chemical compound is a substance of definite
chemical composition, which is composed of two or more elements. Over
750,000different chemical compounds are known.
Examples
of chemical compounds are water, (Oxygen and Hydrogen abbreviated H
Most substances are not simple chemical compounds, but are rather mixtures or aggregates of various compounds. Wood, for instance, is composed of Carbon, Hydrogen, Oxygen, and a small amount of mineral matter. Wood, however, has not a definite chemical composition, and is not a single chemical compound. Likewise the air is a mixture chiefly of two gases, Oxygen and Nitrogen.
Chemical Changes.
A chemical change involves a change
of chemical composition. The grinding of wood into sawdust is a mechanical
change which does not affect the chemical composition of the wood. Burning of
wood, however, is a chemical change.
The burning of wood consists in combining the Oxygen from the air with substances composing the wood. Without the added Oxygen, wood will not burn. After the wood is burned, if all the gases given off are collected and analyzed, it is found that they consist of Carbon dioxide and water vapor. A slight residue of mineral matter in the form of ash remains. Hence,
wood Oxygen yields water+CarbondiOxide+ash
In a similar manner the burning of gasoline in an automobile results in water vapor and Carbon diOxide. This can be seen by watching the steam issue from the exhaust pipes on a cold day.
gasoline Oxygen yields watervapor+Carbon diOxide
Page
18 GO
When chemical elements combine in such a manner as to form more complex substances from simple ones the process is called combination. The reverse process of breaking more complex substances down to form simpler ones is called decomposition.
Example of Combination:
4Fe+3O
Iron +Oxygen yields Iron oxide
Example of Decomposition:
2H
water yields Oxygen+ Hydrogen
Indestructibility
of Matter.
In all chemical changes of whatever sort,
it has been found that if all the materials are carefully weighed both before
and after the change, while allowing nothing to escape in the meantime, the
weight of the material taking part in the change before the reaction will be
exactly equal to the weight of the products resulting from the reaction. This
is true not only for the whole, but is also true for each individual element.
Summary.
All events on the face of the earth involve
in one way or another the movement or change in the relative configuration of
matter. The rains and the flow of water, the winds, the growth of plants and
animals, as well as the operation of automobile and factories are part of the
movement of matter. Matter moves from one place to another, from one physical
state to another, or from one chemical combination to another, but in all these
processes the individual atoms are not destroyed; they are merely being continuously
reshuffled.
GO Top
Links to lessons
GO preface