As you saw in the video "Quest
For Fire" (note to parents: my edited version), the first great discovery
in the course of human civilization was how to make fire. Fire was used
prior to that time, but it had to be found (lightening) or stolen from
other peoples who had it. Fire provided light, warmth, hardened sticks,
protection from wild animal, cooking meat and softening bones to retrieve
the sweet marrrow, fracturing rocks and much more. It extended the range
of migrations.
Most importantly, it eventually lead to
the development of new tools. Clay pots were made, ores were smelted and
forged, soap was made from ashes, sand became glass and much, much more.
It is thus appropriate that we begin our physical science studies with
making fire.
I have chosen fire by friction as
our method. It is described in detail in these two web sites which are
assigned
readings:
Resources
Caveman Chemistry fire
page
Dr. Dunn's Lucifer
page
Background Notes
States of Matter
Solids - Definite shape and definite volume
Liquid - Flows and takes the shape of its container
Gases - Contract or expand to fill their space
(neither definite shape or volume)
Composition of Matter
Substances
An element is a sample of
matter made of all the same atoms.
A compound is a sample of
matter made of two or more elements. The
ratio is always
the same.
Mixtures
- two or more compounds in varying proportions
Heterogeneous
- Can be separated by physical means
Colloids - heterogeneous mixture that never settles
Suspension - heterogeneous mixture (solids in liquid) which
will settle out
Homogeneous
(solutions)- Must be separated by chemical
means.
Combustion
Combustion of cellulose (aerobic)
(CH2O)n
+ O2 ------> CO2 +
H2O + heat
The residue of wood combustion is ash - noncombustible
minerals
Charcoal (anaerobic )
CHO -------> C + H2O
Combustion of charcoal
C + O2 ------> CO2 + H2O
Ashes
A fire that
has some air may result in a mixture of charcoal and ash. This is a heterogeneous
mixture which can separated by physical means. Charcoal is insoluble and
also will float due to air pockets in it. Some portions of the ash are
soluble while other portions have a density greater than water (i.e. they
sink). These components may be separated by physical means. At one
time wood ash was used to make lye to be used in manufacturing lye soap.
We will pursue this further in our next project - Potash
Criteria
Project
|
For your project, you will work in tribes of three to produce fire by the spindle and fireboard method described in Caveman. If you make a flame you pass. |
Quiz
If
your tribe fails to make a flame, you can always get credit by making a
100% on this section of the next test. Here are the subject areas you will
be quizzed on: